A good very basic book for beginners in bass guitar is:
"You Can Teach Yourself to Play Electric Bass"
It sells for about ten bucks and starts out with the most fundamental of lessons...learning the names of the parts of a bass guitar, it also teaches sight reading, and typical basic points of playing a bass.
If you feel you are a little more advanced than that, another good book is:
"Building Bass Lines" with CD by Chuck Archard, Alfred Publishing, 95 pages, $19.95
This uses both standard notation and tab and is chock full of valuable information.
Both of these books and others are available at:
http:
www.bassbooks.com
I bought mine in music stores, though. They are commonly available, also in book stores like Barnes and Noble.
jo