I'm a guitar player but I guess the advice would be the same.
You're right to start out with a lower priced bass and amp.
I'd get the amp too so you can really hear how it sounds.
Learn on it and if you decide you really want to be a bass player,
and as you learn more, then trade up to a better bass and amp.
There's allot of books and videos out there.
One of the oldest companies is Mel Bay.
You can usually get their books at any music store worldwide.
I'd start out learning notes and scales first, then move on to chords.
After you learn that, then start thinking about what kind of music
you're gonna play, and jump into that style and see what happens.
Here's a list of books and video's Mel Bay has: