I've never been a beta reader for someone before (unless you count my real life friends and their essays or short stories to hand in), but I am willing to try. I will help you with your grammar, spelling, or punctuation mistakes. I will also try to point out awkward phrasing and the likes, and I will give you my overall impression. Basically, I'll do my best to help you with your story in any way I can, but I won't be able to suggest story ideas to you. I never flame, and if I have any criticism, I'll be as gentle as possible.
I'm quite fast to respond to emails, but I usually use my computer only on Friday and the week-end, so please don't fret if you don't get a reply right away.
As for the categories I will beta for, please check the list above. I'm in the middle of reading Bleach and of watching Durarara, so my knowledge about these two fandoms might be limited, but I will try to beta them for you if you want to.
I might refuse to beta occasionally, but there would always be a good reason. Otherwise, I'm always open for betaing! C: If you want me to beta for you, just send me an email through the contact author button thingy, and please indicate your Lunaescence username.