I can be a beta for stories that go AU (Author's Universe). I'm not much of a fan of canon after book 4, and I absolutely despise canon fics that just regurgitate the books, especially if they just swap out characters, say Ron for Draco, or Hermione for Pansy, regurgitation doesn't work... If you want to write, make it AU, make it YOUR universe. That is what writing is actually all about, unless you're a plagiarist, then well you're something I stepped on a while back and I'll wipe it off later.
Stuff I enjoy... independent Harry, Harry/non canon pairings, basically Harry anyone other then Hermione and Ginny, flawed Dumbledore, flawed Weasleys.
I don't read slash, ever... I don't understand how people think no matter how well it's written that Harry would hook up with Draco, and or Snape, the people that write those, I don't understand their mentality. It'd be like taking your biggest bully while growing up and becoming their lover... I don't know if this happens regularly, but I think back to my high school/elementary days, and I would not be hooking up with those that were bullying me, (and as a ginger I did receive a fair amount of it).
Why I don't like canon pairings, first Harry Ginny... that match to me just seems doomed from the start, I know there is a saying out there that guys marry their moms, but in this case in point JK kinda made it so disturbingly similar, with other teachers stating how Ginny reminded them of Lily. Now I understand that was piss poor foreshadowing into who he would eventually marry, but I don't get the attraction at all, and this is another pet peeve of mine about fan fiction, is you all have people prettied much married off in high school, (Maybe that's why the divorce rate is so high nowadays). You're not going to find your true love, unless you're extremely lucky, and even then I'd check back home when you're supposed to be at work, from someone you met when your hormones were going crazy, and you WERE ACTIVELY SEEKING A MATCH!
Now Harry and Hermione, could be a match, but I feel it's been done to death, because so many people love harmony.
Which leads me to my next point, HP fan fiction doesn't need to focus on taking down Voldemort, (As I'm typing this I'm finding it odd that the only errors I'm getting in my spelling is Weasleys and Snape). Voldemort can be dead and however you want him to be dead, horcruxes or no. That's the fun of fan fiction is it allows us to enjoy a world we already love even more. If you didn't like the treasure hunt JK sent you on, make your own version of events that happened, it doesn't have to be long, just maybe 1 or 2 paragraphs explaining how Voldemort was a useless twat and ended up being suctioned into a toilet.
I can't remember the author, I'm pretty sure it was bobmin (RIP) but they did a brief recap of how Harry was surrounded and he pulled a spell out of his ass that would make it look like suicide thus horcruxes self imploded... Actually I think that was from their parallels story. But I also remember him writing while he was writing on mutant storm, that he was tired of dealing with Voldemort, and I remember writing him a review, that he shouldn't concentrate on Voldemort, if Voldemort isn't part of the story. AU means AU for a reason, write your story! He went on to write the Dragonriders trilogy, and to me I feel that should be purchasable content as before he passed away is storytelling gold.