The only way to get to Chuuk (Truk Lagoon) is on Continental Micronesia from Guam.
Go to
Continental Airlines - Airline Tickets, Vacations Packages, Travel Deals, and Company Information on continental.com to check out the flights.
Getting from Saipan to Guam there were several options last time I checked.
In my opinion, the week long Liveaboard "Odyssey" is the best, hands down. I have been on 2 charters 10 years apart and both trips the operation was impressive.
Welcome Aboard the Truk Odyssey - Wreck diving in Truk Lagoon Micronesia
Land based is really not a good option in comparison. There are two operators that have a hotel & dive shop but its just not a good value. There is another liveaboard, the Thorfinn. But if you research the Odyssey you will see how it gets high marks.
If you want someone to handle the entire issue (getting from Saipan to Chuuk & back, book the dive trip etc.) you can contact MDA divers on Guam, they have a fully competent dive travel team that specializes in Micronesia.
MDA Micronesia and Pacific Travel
You will NOT get tired of diving the wrecks in Truk, There is so much life on them they are like artificial reefs, so even if you are not big on wreck diving you can still enjoy the reef life.