In reply to An Triubhas:
It covers all areas of the Peak - about 4000 problems I think.
There are a few links to printable topos, but you won't find many of these. The site is more geared towards being a database that can be added to by anyone. This means that photos, videos, new problems and information can be easily shared.
If you have an iphone or similar, you'll find pb.info quite useful when you are at the crag. If (like me) you don't, printing out the list of problems at the crag should give you a decent idea of what's what.