William Annis' twin sites Aoidoiand Scholiastae are great resources for annotated Greek poetry and prose, respectively. I have not delved too much into the offerings, but what I have seen is impressive.

My favorite resource on Scholiastae is Greek Grammar in Greek (PDF), which provides vocabulary and some introduction for the discussion of the Greek language in Greek. I appreciated this so much that I made a Quisition flashcard deck of these terms.