Manipulating MP3's?

1

I’ve got a book on tape in MP3 format, but it’s all one track and I’d like to retool it into many tracks as to enhance my ability to reference it. I’d also like to alter the bit rate at which it is compressed so that I can fit more of the book on my MP3 player at a time. Can anyone suggest programs (freeware is better but not necessary) that can help me accomplish this?