In reply to puppythedog:
Your best bets would be:
1. Get hold of the "North Wales Bouldering Guide" by Simon Panton, only problem is they're rarer than hen's teeth so unlikely to turn up, I got a second hand copy on here.
2. Get a copy of "Boulder Britain" by Niall Grimes, it's supposed to be a pretty good guidebook and easily available.
3. Use topos from the North Wales Bouldering and Hongian Bouldering websites
http://www.northwalesbouldering.com/topos.asp and
http://hongian.cymru/ for recently developed crags in combination with the definitive guides which have reasonable coverage of the major boulders.
4.. There's been some talk of a second edition of the Simon Panton guide which is meant to be coming out this winter, although Ground Up are known for producing very high quality but not particularly punctual guidebooks.