Unless you're a licensed builder (if you're here you're probably not) you'll need to learn as much as you can about basement remodeling if you want to complete the project successfully. Being here is a good start!
I checked out 30+ books from the local library to help prepare myself for the project. Some were specifically about designing and finishing basements, some about designing and building walls, etc. I also read two books on drywall alone!
Here are a few remodeling books that were particularly helpful:
While it's great to be able to check books out of the library, you'll probably want to purchase a couple of them to keep around for easy reference. I've purchased the ones listed above. I think they'll come in handy throughout the project.
I've also become a big fan of the DIY network on cable! They have many shows that demonstrate the tasks you'll be completing as you finish your basement. I'd also recommend you check out their Web site at: www.diynetwork.com.
There are also many good DVDs and videotapes available that will help you as you complete your remodeling project. Whether you decide to finish your basement yourself, or leave it to the professionals, the more you know about the process the better off you'll be.