I love answering questions and helping people out (especially with technical stuff that is confusingly explained elsewhere, or hard to understand). I read a lot so if there's something I don't know well, usually I will at least be able to give a point in the right direction.
I'm not very prolific art-wise, so if you're concerned with me not knowing what I'm talking about, I'll be sure to provide full explanations, links with cites, rival ideas on the subject, whatever, and I'll say immediately if it's something I don't know well.
Here's what I can help with and to what extent:
Perspective: Intermediate (though if you have any question, I will try my darnest to find out the answer)
Anatomy and proportion: Beginner
Anything else: ask.
If you're a beginner, I can be nice and gentle with criticism without dumbing anything down. This stuff is fascinating, and I'm of the opinion learning art should never be boring or painful, and one can learn faster if it isn't.
Don't be shy. Ask me anything!
PS: If you're around my level and just want a Sketchbook buddy, or someone to talk about art with, work stuff out with, whatever, I'm totally up for that too.