I'd recommend browsing through the fics here at the com or checking out The Moonshadow Archive or the Snupin Library reccomendations if you are in search of more fics about this pairing. ;) The lupin_snape user page should have more helpful links. Trust me, you'll find tons of fics that are infinitely better than anything of mine.
Welcome aboard! I'm relatively new myself, and have only done a few other fics aside from this. All of them have been posted to this com and its mirror over on lj.
Oh! And be sure to watch the Snupin Prophet! I've found it to be quite helpful in finding new Snupin stories to read! ;)