In reply to Rob Laird:
The 2008 Climbers' Club "Southern Sandstone and the Sea Cliffs of South-East England" is the definitive guide, although the Jingo Wobbly "Sandstone Climbing in South East England" has more topos and covers all of the major crags but has a few errors. I use both but the former tends to be favoured.
Cheers, Rob.