I thought it might be a good idea to have a thread like this.
Post some good resources, references, stores, videos, tips for general use.
https://mega.co.nz/#F!WBAlWbAY!OHlVpL_6vsusinFzniu4_g
A giant, huge pack of Art related books. A good 17 gigs worth of books, references, brushes, screentones and more. A really nice find and extremely helpful. This also contains some NSFW material, mostly artistic and mundane but hey, DL at your own risk. Also some books may be in japanese/moonspeak, good luck with that.
http://www.posemaniacs.com/
Helpful reference site of movable 3d models, helpful for anatomy reference and general use.
http://www.sketchdailies.com/
For me this is a great source of inspiration.