Hi Marcus, have you just bought them or are youloking to be a master on them!?
If you're a beginner (like myself) then I found the pioneer prodj forums (google it for the addy) to be quite useful, although (and be prepared to be told this 100's of times) the best advice is to play with them yourself!
The main hints and stuff comes from 'turntablist' types, so it's more on scratching and stuff.
(oh, and I found that downloading the US manual was a help, so you don't have to trawl around the french instructions!)
Possibly the only little hint I can give you, is to set the 'brake' level, so that the dzzzzeeeeeuuuuwwwww (time taken from pressing the start/stop button and the tune actually stopping) lasts exactly 1 beat (or a millisecond over) as IMO it sounds cool when you press it press it one beat before the breakdown of the next song, if that makes sense!
Oh, and don;t get disheartned if you're shit at setting loops. Everyone is at first apparently, and practice makes perfect (well, better!).
Finally, as muchs for the first few months, you'll love flicking the record back and forth over the 'in' beat to cue it up, stopping it, cueing it just behind the 'b' of the first beat, and then pressing play (although may feel like 'cheating') actually works better IME.