How you found the community or the earliest community experience you can remember: Now, I really don't remember! At least three years back, I should think, and I expect I followed links from somewhere to somewhere else, and ended up here (OK, on LJ, but you know what I mean!). And then I probably lurked for a while. I'm a born lurker.
Why you ship Snape/Lupin: Two strong-willed men with very different canonical views of things - there's bound to be something interesting going on when they get together!
Link us to your first post or reply on Lupin_Snape: Well, it would have been a comment, but I honestly don't know *when* - as I say, it would be at least three years ago! And I'd have absolutely no way of tracing it... Possibly on something by busaikko, scribbulus_ink or bronze_ribbons?