Muscle soreness

Ok, I’m pretty sure that this question has been asked before but anyways… I remember reading Mr. Berardi’s article (I believe it was Bring on the Pain 2, not sure, it was maybe a month ago so the memory is kinda foggy). In the article, Mr. Berardi addressed muscle recovery from workouts and some of the biological mechanisms of recovery. The one thing that stuck in my mind was that you mentioned that you should wait for your soreness to heal up and rotate different muscle groups so you don’t continually break down your muscles as they are in the process of regrowing (which is why you mentioned some people don’t see any gains or significant ones at that). I believe you said this could take anywhere for 1-3 days. Anyways, what I want to know is exactly how "un-"sore can you be before you start working that muscle group again? I just started working on my abs (till I passed out from exaustion) about 4 days ago and I’m still sore slightly (is it my diet or just how my body works? Remember I said I just started so…?) Once the soreness goes away, and I start again to increase the load, will I get sore again and have to wait or what? Are there any ways I can make my recovery go quicker? Thanks.