Struggled to get to grips with this technique when I first became aware of it (Kajagoogoo, Level 42, that kind of era). I suspect because A) I didn't appreciate the music associated with it and B) I liked being told I was good so didn't want to risk revealing I couldn't do something. I therefore simply told people I refused to play slap bass as a matter of principle.
I am now trying, in a spirit of learning and humility, to achieve a basic facility in the style.
This Hal Leonard book wot I purchased from this parish, is proving useful.
Clearly laid out and explained, with ground up exercises in steadily increasing complexity, the book is very much the thing for a total ignoramus such as myself.
There is a CD with it but I've not checked that out yet. The best resource I've found to accompany the lessons is the Youtube drum channel LumBeat. There's something about locking in with a real drummer which brings even the most bassic bass lines to life.