When John and I first decided to go to Guam we knew next to nothing about it. I tried to do some research, but the Wikitravel page is pretty sparse and most of the travel blogs I found were from people in Hong Kong or Singapore traveling to Guam specifically for shopping. While they were helpful, I didn't find that they spoke to our situation, which granted is pretty unusual. The majority of people who visit Guam are Japanese, followed by Korean, Chinese, and Russian tourists. There is a big military presence, but I can only assume that if you're military there are all sorts of informational resources available to you (and you're probably less interested in hotel quality and how to ride the hotel - shopping center trolleys). It seems that very few people visit Guam from the mainland US, and to be honest I'm not even sure if there are direct commercial flights. Guam used to be a hub for Continental airlines (I even connected there in 2010 on the way to Tokyo from Tonga), but since the merger with United I think it's seen less traffic.
This post will be nowhere near comprehensive, especially considering how much time John and I spent just lying by the pool, but it's a lot of the information we were curious about ahead of time, so I hope it might be helpful to other people in a situation similar to ours (English speakers, living in Asia, vacationing in Guam).
Airport: The airport is pretty small, but sufficient for the traffic it handles. Entering the country was very simple for us, being US citizens. While everyone else had to go in the long lines for immigration we only had two other citizens waiting in our line. Of course, if you fly in on a flight heavily dominated by US citizens you'll have the opposite experience, unless you're not a citizen yourself. On the way out of the country it took us 45 minutes to check-in and make it through security. Lines move quickly, but they're extremely long, especially with tour buses dropping big groups off frequently. Be sure to give yourself time. Duty free and souvenir shopping in the airport was unimpressive. We found the selection and prices to be better in our hotel gift shop, in Kmart, and in the ABC stores.
Taxis: All taxis on the island seem to operated by the same company: Miki's Taxi. At the airport there is a counter with flat rates to all the hotels listed. You pay at the counter and then they direct you to a taxi. Our fare to the Marriott was $15 plus $1 per bag. (On the way back to the airport we were not charged for bags). Most hotels are in the $15 - $20 range, but we noticed that Leo Palace (a company that rents lots of temporary and furnished apartments in Japan) was $50! From hotels and other typical tourist locations there are often stands with estimated prices listed, so you shouldn't ever be surprised by a fare. We found taxis unnecessary during the week, either walking or using the Trolley system.
Hotels: The truth is that this is a tropical island with a lot of humidity and not a lot of competition (and we've gotten spoiled living in spotless Tokyo). When we first arrived (at 2 AM) we were not happy to find that our pricey Marriott room had worn out carpet, cracked wall paper, and those annoying fabric shower curtains that water always goes straight through. But within a couple days we had adjusted and felt like it was an ordinary (though not fancy) room. The beds were comfortable, the towels were clean, there were no bugs, and everyone was really friendly. What really made the hotel were the amenities. It was beach front, which was important to us, and had a gorgeous pool with ample seating and a convenient pool bar. We didn't have a lot of plans to leave the hotel, so we wanted to be comfortable on the premises, and while our room wasn't great, everything else made up for it. My advice when booking would be that if you want a really nice room you're going to have to shell out A LOT for the Westin of the Sheraton. If you don't care so much about the room, and you have plans to be out most of the day then the lower tiered hotels (like the Fiesta) are probably just fine. If it's in your budget and you want to be able to relax at your hotel and value the pool/beach access, but don't want to shell out for the fanciest hotels, go for the Hilton and Marriott tier. At the Marriott specifically, internet is $15/day but if you sign up at the front desk for Marriott Rewards they waive the fees. We were there for our anniversary, which we mentioned, and they very thoughtfully gave us a bottle of wine and chocolate covered strawberries on the day. I find touches like that very endearing.
Trolleys: We considered renting a car to explore for a day, but in the end were just too lazy. There are red trolleys that run a number of routes through the island that we found perfectly convenient. For $25 we purchased a 5-day pass, which seemed to be a good deal compared to $4 fares each way. You can buy the passes from the bus driver in cash when you get on. The shuttle that runs between all the hotels and shopping centers (clockwise and counter clockwise around the island) comes about every eight minutes. There are shuttles that runs between DFS Galleria and Kmart, and Premier Outlets and Kmart every twenty minutes. From DFS there is also a shuttle to Two Lovers Point. A round trip ticket costs $10 (the 5 day pass isn't good on this route) and can be purchased on the bottom floor of DFS This is the only place that we ever found schedules and brochures in English. The red signs at the side of the road are in English and Japanese, but almost all brochures are in Japanese (katakana) only.
Shopping: One of the funniest things I read about Guam was that it has a huge Kmart. In the little information I could find people were going crazy over how this was the biggest and best Kmart in the world where the aisles were crammed with just about everything. I'll admit there have been more than a few days when I have longed for a Target, so I was excited to see what this Kmart had to offer! The truth is, it's nothing special. It's basically identical to the one in the town where I grew up. We were able to buy toothpaste, deodorant, and american candy, but it wasn't worth getting excited over. (At least no more than familiar brands of toiletries and candy warrants). Besides the Kmart (which incidentally is less than a ten minute walk from the Marriott) there is lots of shopping on the island. In fact, you'll find the beaches aren't crowded at all because most of the Japanese tourists are busy shopping. There are three main shopping centers that the trolley will take you to: DFS Galleria, Micronesia Mall, and Guam Premier Outlets. DFS is the most high end, and doesn't have a food court inside, though there are plenty of options in walking distance. Micronesia Mall seemed the most tired, and the Outlets were in the middle. One of the anchor stores is Ross (which John loathes) but they have several shoe stores as well, so I was able to get a new pair of tennis shoes finally! Yay for stores that actually sell my size! All over the island there are ABC stores - not the liquor stores, but the tourist convenience stores that also exist in Hawaii. They are easy to find just about anywhere and their prices on sunscreen, souvenirs, and snacks seems to be pretty competitive.
Eating/Drinking: While in Guam we decided not to eat anything that we could easily get in Tokyo, so this is going to focus a lot on the American food, but if you're not from Japan there is a huge selection of ramen, sushi, and Japanese steakhouses that I assume are decent. Our biggest goal while we were there was frozen yogurt, and I am happy to report that not only did we succeed, we managed to have it three time in the five days we were there. Swoon. (And the best part is that in a week of eating tons of frozen yogurt, american food, and drinking beer at the pool every day I lost three pounds! I can only conclude that this means I was meant to exist on fro-yo.) Micronesia Mall and Premier Outlets both have frozen yogurt places inside, and there is one in walking distance of DFS, just in case you needed to know. Micronesia Mall has a pretty substantial food court with all the usual suspects like Subway, Panda Express, and Sbarro. The outlets have a smaller food court, but outside the mall there is a movie theater, a Wendy's, a Chili's and they were building an Applebee's. Our tactic was to take the trolley to one of these places for lunch (after sleeping late) and then spend the rest of the day by the pool or the beach. On our anniversary we had dinner at Proa which is one of the highest rated restaurants on the island. I thought the food was fine, but the atmosphere and the desserts really shone. Another night we went to a Mexican place called Margarita's. We wanted so badly to like it, but truthfully it wasn't very good at all. Even the margaritas were disappointing. The atmosphere is nice, but I've had better Mexican in Tokyo, which is saying something. Another night we went to the Jamaican Grill across from our hotel and we were very satisfied. The portions were enormous and it all tasted great. Other than that we just tried to eat as many salads and sandwiches as we could.
Weather: Guam has a tropical climate with highs around 85 and lows around 75 most of the year. We were there when they were getting "bad weather" from a storm out at sea. Honestly it was a little windy and we had about 30 minutes of rain, but people kept apologizing. Basically, it's paradise. Just keep in mind that July-December is rainy season. And don't forget to slather on the sunscreen, there is no faster way to ruin a vacation than with an uncomfortable sunburn!
Additional Thoughts: I've read that Guam is a poor man's Hawaii. I think instead I would say it's a Japanese person's Myrtle Beach. The majority of the tourists are Japanese, and that was a little odd. We were able to speak English everywhere and use US dollars, but visually we still stood out a lot. Most of the time we were the only white people on the trolleys. I suspect people were unsure if we were with the military or Russian tourists, and were surprised to find out we came from Tokyo like everyone else. There are plenty of seedy strip malls with shooting ranges, tattoo parlors, and strip clubs, but that stuff is pretty easy to ignore (unless you're looking for it). What I thought was fun was how much the Japanese people let their hair down and relaxed, wearing casual clothes and letting their hair go wind blown. All in all it was a pretty random trip, but completely enjoyable. There's not a lot to do, but if you're looking for a tropical place to relax, Guam has got you covered.