I don't read H/G (actually, I don't read anything that ships Draco or Ginny with anyone else - I mentioned being insane, right?), but my friend Fearthainn likes them for canon, and she's friends with r_becca and loves her writing, which I trust as Fearthainn isn't someone to like bad fic. hpgw_ficafest was mentioned at one point as being a good source, and SugarQuill is all about the H/G. And that's about the extent of my H/G knowledge, but hopefully it was helpful.

And the Lexicon is awesome. I use it all the time, because it's a lot faster than trying to find the one mention in the five books of one single tiny item, even with Word's search function.