I'm dusting off my old LJ account just to post the art resources and stock that I have bookmarked. I can't promise these links will work forever, but hopefully enough of them will remain.
Art lessons/instruction:
Andrew Loomis instruction booksGlen Villpu's YouTube channelDan Gheno's TEACHINGSArt Kink tutorialsExplore Drawing and PaintingSheldon's Art AcademyArt instruction at pixelovely --it started with their gesture drawing tool, and now she's really expanded it to include tutorials and resources.
Human anatomy resources/stock:
Anatomy References for ArtistsPosespace.com --this one wants you to buy their full-size images, but the preview images work just fine for gesture drawing/anatomy practice. Fine to use for practice, not fine to use for commercial use.
Grey's anatomy scans onlineA Guide to Human Types part 1part 2part 3 Pose reference/stock:*
Bodies in motionReference! Reference! --technically animation resources, but it's great to see things in motion for reference
Other stock/resources:
MorguefilePhotovault --these are not royalty-free so do not use them for anything commercial
*Posemaniacs is not a recommended resource for poses. Why? Because it's like a glorified ball-jointed doll that has muscles painted on top. The shape of your body changes as you move your muscles around. Muscles and tendons are not static: they move. Muscles stretch or bunch up, which does not happen with the Posemaniac model poses. I'm sorry if you love Posemaniacs, and I know that there are people who swear by it, but it's not that great of a resource due to its inaccuracies. I really can't recommend using Posemaniacs because of this.