General Pointers

1. Use a practice book that teaches basic scales in varying note and time patterns (this assumes you read music, obviously). [The book I've used most often is an old one (probably out of print by now) called "Bass Guitar Scales & Melodic Patterns" by Jay Friedman. It's published by Dale Zdenek Publications, 1978.] This will teach the scales themselves and also the playing of more and more rhythmic patterns. Initially, the only thing to focus on is playing the right notes. As you become comfortable, I suggest using a metronome to help develop a sense of time.

2. If you can get a subscription to (or even a newsstand copy of) Bass Player magazine (Miller Freeman Publishing), the issues have excellent practice examples at the back in a serial format. I'm not sure where you're located; if you need info on subscribing, they have a web page at bassplayer.com.

3. Play along to the tunes on your favorite radio station-- I've often found it helpful just to jam along with whatever happens to be on. This helps to develop your listening chops and well as providing a forum for improvising. Kind of like sight reading for the ears.