I've got Mark Levine's book, but I've also got another one (bright red A4 size) called 'Jazzology'. I prefer it because it's clearer. The sentences are short but very well written because they're unambiguous. Lots of people like the Levine one though.
I would recommend learning the major scale first and then the major scale modes. You can do this using this resource:
http://www.studybass.com/tools/chord...-note-printer/
I have organised my practice as follows.
1. Pick parent scale (there are four, major, melodic minor, harmonic minor, harmonic major). So far I have just started melodic minor. There are other scales too that have more or less than 7 notes, I'm just picking these four because it gives access to a lot of of stuff to begin with and it's a lot of work all by itself, and because I can compare them.
2. Learn all the scale degrees by the name of the mode they start. I do this by drawing the diagrams whilst away from my bass too (for example when on a bus)
3. Practice grooving and improvising in each mode from the very start, and basically looking at the shapes for things I find interesting harmonically.
4. Practice stepwise motion, tertiary motion, and quartile motion. This means also practicing scales, tertiary harmony (standard western harmony) and quartile harmony ('sounds jazzy' harmony).
5. Move on to next parent scale.
6. Once I've done all the parent scales and their modes, learn which modes apply in which musical situations.
7. Learn what every note is on the fretboard.
I think what I'm also treating as essential is that improvisation happens throughout the entire process of learning.
I'm also trying to develop an awareness of the modes and different parent scale modes that preserves a feel for the underlying parent scales. Rather than say, just learning them in isolation as variants of the major scale.
