Other Coast Guard Boot Camp Resources
Official Coast Guard Websites
The official forum of the USCG. You have to register (it's free and takes 2 seconds) to post anything, but there's lots of useful info on there that you can read through without registering. People are very helpful and you will often meet people that either just came back or are going to be shipping out at the same time as you. Kudos to the moderators over there for running a great website.
The official website of the United States Coast Guard. The main page isn't that helpful for preparation, but certain sub-pages are. I'd start with:
The official blog of the United States Coast Guard. This website isn't going to help you too much with preparation, but it serves more as a current events site to give you an idea of what's going on in the Coast Guard.
If you are going to DEPOT training then this is the broad overview of DEPOT. It gives you a very basic idea of what to expect. For more useful info, I strongly recommend registering at the official forum (the 1st link on this page) and finding the DEPOT sub-forums. There are always recent DEPOT graduates answering questions for those getting ready to go.
If you are planning on applying to Officer Candidate School for the USCG, these are all the forms you need and all the deadlines you need to meet.
Un-Official Coast Guard Websites
The woman that owns this blog went from enlisted to officer and has served in the Coast Goard for over 15 years. As of the time of this writing, she seems to have stopped updating the blog but you can search through old posts to get some insight on "a-day-in-the-life" type stuff.
The information on here is a little bit dated and some of it isn't valid anymore, but overall it's still a good read to give you a broad overview of what Coast Guard Boot Camp is like.
Four other websites that have some information on the Coast Guard. Not all of them are helpful for boot camp preparation but if you are interested in learning about different USCG related topics then check them out. The last one is actually a Company Commander home page.