Welcome to the forum!
I can only speak with regards to KMWW(offcially released by them). There are other Krav organizations but I really have no knowledge of those.
There is the Complete Krav Maga Book by Darren Levine and John Whitman, excellent book by the way. If you head for KMWW's ProShop you can see what's available. There are other books and such but this will get you started. There's like 2 errors in the book but you can find those in the KM books and technique section. I'll bump those up for you
As far as ATA - there have been a few talked about(some in FL seems). I think our instructor folks who post here can help ya out
. You'd need to look at how KM is being presented. Is it just moves being mixed in with other martial arts? At my center, you typically do a cardio type warm up (could be jump rope, shadow boxing, etc), then comes the KM techniques themselves. Depending on the class, you could be partnered up, in groups of 3 or more and so on. It depends on what's being taught.
Hope this helps some