Reddit mentions of Aesthetics: A Comprehensive Anthology

This article, this VIS, and this anthology ought to be more than enough material to get you started.

Don't know if you'd be interested in these but I have:

Readings in Medieval Philosophy: This one is kind of falling apart.
Aesthetics: This one is like new. It might have some light pencil marks inside (though I'll double check to be sure that's it), but I barely used it. I bought it for a philosophy of art class.
Interpersonal Communications: Pretty worn, some writing on the inside. Pencil, definitely, maybe some pen as well.

If you're at all interested in any of these, I'm interested in Brave New World and Dune. : )

I would probably have to go with Heidegger's essay The Origin of the Work of Art, if only because I'm a big Heidegger fan. He's not as big on aesthetics though, so for that I might go with Nietzsche's Birth of Tragedy.

If you're looking for a decent overview, this was the anthology of philosophy of art class used. Was pretty good and hits on all the major thinkers, as well as some less-known ones, so you can follow up wherever you find something interesting. Also for a contemporary art history course, we used this pretty extensively. There are some anthologies that would cover some older material if you're interested and find a period you're drawn to.