The book already mentioned is a must have. I like Bass Guitar for Dummies as a starting point you may find a copy in your public library. The graphs and patterns are very good.
Dummies will have all the how to's. How to hold your bass, how to tune it, how to get sound from it, and how to mute some of that sound, things like that. The fundamentals.
Online Bass Lessons at StudyBass.com is well worth your time. The first couple of pages go into detail how we should use our bass.
Some things you will also want.
An electric tuner. $15 - $35
A metronome. Free on the Internet or $15 to $35
A guitar stand. $15 to $20
A music stand. $15
Think about a soft gig bag. You really do not need it now, but, when you start taking lessons you will need some way of lugging that beast around. $35 - $50
An amp. 10 to 15 watts is enough for practicing. $150 -$200. Get one that has an earphone jack, so you can practice and not disturb the family.
A cable from the bass to the amp. $15 - $20.
Lessons. $75 for 4 weekly 30 minute sessions. Best $75 you will ever spend. Couple of months to get started, it need not be a lifetime thing.
Welcome to the bottom end.