Springhouse also makes "Incredibly Easy A&P" and a lot of other incredibly easy books.
Also for math classes to get a jump start "Cliff Notes" has some good pre-algebra, algebra paperback books they can be purchased in the book sections at say "Wal-Mart"..etc. also online at Amazon
.com and other online bookstores.
Julie is right, you will learn a lot in class and if you have a great instructor that will really help.
I think instructors have a lot to do with how well you learn in class. See if you can use a tape recorder to tape lectures.
Also there are helpful internet sites that you can go to for help on certain areas that you want to brush up on i.e. Math, Eng, writing etc.
I personally like "Google" as a search engine and find almost everything I need there.