I would recommend the Lonely Planet book on Micronesia, available at any good book store, a competing book series by Moon Publications writes a travel companion book for Micronesia as well, get both as they are excellent.
Truk (now called Chuuk) is a small grouping of islands within a huge atoll. If you really want to get around these islands you will need a boat. (I think these services are quite common and not too badly priced but still check around). Hotel lodging is a bit of a challenge as you need to book well in advance from what I've heard. The Truk Continental Hotel is the biggest one there I believe. There are a few smaller "mom and pop" motel establishments there too. The tourism market caters primarily to scuba diving in the huge atoll.
Truk served as a huge Japanese naval base during WW2 and was the scene of "Operation Hailstone". This US aerial attack on the Japanese fleet at anchor there, littered the bottom with countless wrecks that you can now dive on. It's a huge underwater park now. The whole atoll is a living history museum!
As for connections, "Air Mike" (Continental Micronesia) is the only game in town. I've flown them several times when I was stationed at Guam. BTW: It's sometimes jokingly referred to as "Continental Monopoly-nesia" (G). Air fares in the area are a bit high, but with some planning you'll do ok.
The long distance flights from GUM-HNL are operated by Continental, as are the IAH-HNL runs. Northwest -used- to fly the GUM-HNL wotuing but lost their rear-end in that market and pulled out. Indeed, CO operates the DC-10-30 (as did Northwest at the time they flew there)
The only real "competitor" to 'Air Mike' is Air Nauru. Their selection of flights though is much more limited than Air Mike. Their flights originate mostly from the tiny island state of Nauru and fly to a limited selection of Micronesian destinations. They've had trouble lately with their operating certificate revoked but then re-instated, be forewarned their schedule is known to be chaotic with frequent cancellations. I've heard it's competitive on a price basis with Air Mike. (if you are lucky to get a flight on them though! (G)
If you want to trek a little eastward to Majuro and the Marshall Islands, Air Marshall Islands operates a selection of flights to various atolls out that 'neck'o'the'woods' as well. Overall though Air Mike is the best bet for the heavier distance flying there and they operate a solid, reliable schedule, new equipment also (737-800s now on the multi-stop "Island Hopper" from Honolulu to Guam: which stops at Johnston Atoll, Majuro, Kwajalein, Kosrae, Pohnpei, Truk, then Guam. It used to be with 727-200s and -100C's years ago.) Everything in Air Mikes system eventually winds up at GUM. They operate a brand new terminal there and is said to be spectacular. Connections there are said to be quite convenient up to Saipan (140 miles N of GUM..a nice diversion from the hustle and bustle of Guam too), down SW to Yap and Palau (a must see destination too if you like diving), and off to various Asian destinations like the Philippines, Taiwan, HKG, Japan and Bali. I really like (and miss) that part of the world, you'll love it!
Here are some useful links:
Destination Micronesia/Continental Micronesia
Guam International Airport
Moon Publications Micronesia Handbook/ Australia site
David Stanley, author of Micronesia Handbook (links to handbook on Moon's official site also)
CHEAP Lonely Planet Guide site
World Destination travel guide locator:
Lonely Planet's site on the Federated States of Micronesia
I cant recommend the two books I mentioned/linked here -enough- though, They both helped me save a lot of money when it came to hotels and restaurants, etc. Made the trips I've had into these areas a lot easier.