The following links are mostly links to slash (ie: Snape/Lupin as a couple) websites. If you dislike slash, you may still like the Snape & Lupin mailing list, open to all type of Snape/Lupin fans.

Snape & Lupin (click here to join) (all stories/discussions about Snape and/or Lupin)
Snape/Lupin Slash (click here to join) (only Snape/Lupin)
Comprehensive Snape/Lupin Link Listing (link list to Snape/Lupin fanfic & fanart)
Severus x Remus Club (Deviant Art club for Snape/Lupin, lots of fanart)