Re: slapping
As mentioned above, learn the basic movements first, alternating between
thumb/slaps and finger/pops (finger pops = actually pulling the string away
from the fingerboard and releasing it, creating the note). Then practice octaves
in all positions, and mix it up a bit using different combinations. For example,
using a sixteenth note pattern, instead just T-P-T-P, T-P-T-P, T-P-T-P, T-P-T-P
(where T = thumb and P = pop) try T-T-P-T, T-P-T-T, T-P-P-T, P-T-P-T, etc.
Hope this makes sense. Also check this page out for details on right hand
technique:
http://www.warwickbass.com/basssurvival101/lesson_5slap.htm
It has some little movies that demonstrate the moves. BTW, guitarists can
use this technique, too (a la Van Halen's "Mean Street" intro on the Fair
Warning album).