Center for Adult Learning -- If you'd like to get a GED, here is the place to learn all about it. You'll find the most up to date information and a few good tips here.
GED Practice -- Gedpractice.com is a free service provided by Steck-Vaughn to familiarize you with the types of items you will see on the actual GED test. By answering GED practice questions and getting feedback, you will develop a feel for the kind of reading, thinking, and problem-solving skills you will need to pass the GED test.
GED 2002 -- This site is so nicely done that it looks like a commercial site but it seems to be free. I didn't even register and I was able to navigate through the entire site. Very good practice exams here and you can get all the information you need for the new ged test.
GED Resources -- Very good information on punctuation and math formulas as well as links to other good resources.
4Tests.com -- Excellent online GED practice exam here.