Stan and Zigzag. Keep an eye on this forum as there are quite a few Pentlands rides organised (oh, and apologies to the folk whose e-mail addresses I lost after a nightride a few months ago; I lost the bit of paper which is why we never got back in touch; nothing personal).
Most of the good Pentlands routes aren't on any map, but many of them are only rideable in certain weathers. They aren't sustainable all year round.
As for conditions there just now, expect to push on most climbs, but have great fun on the descents. It's a great time to try some of the descents through fields that you wouldn't normally ride. The snow is so deep you'll definitely fall, but no danger of getting hurt.
The path round the back of Clubbiedean is great just now, as is the one linking Torduff and the Scout Camp.