Wow my background colour clashes horribly with dA's. Sorry about that.
POSES??? I want to stress that this is how I do things, not how you should do things. I mean, you can if you want. But it's entirely a personal thing, as art should be! Always look at other people's art, as they will come up with poses you hadn't even thought of and generally broaden your mind.
Here are some useful links:
pixelovely has photos of life drawing poses and a system that cycles through them like a real life drawing class! You can also pick whether you want just men or women, or just nude or clothed, or both.
posemaniacs has tons of 3D models in poses. They're shown on the muscle layer of things so that you can see how the muscles work! All models can be rotated 360 degrees, and come in varying degrees of camera angles from top to bottom. They also have a fantastic hand viewer which has hands that can be rotated along all axes, although there's a limited selection of poses and the anatomy of the hands themselves could use some work.
Some great stock providers on deviantArt include *SenshiStock, *LaLunatique, aaaand... I can't find the others right now. I'll edit this post when I do!
Anyways, this is extremely helpful. Wow, didn't know line of action could be used for non-dynamic poses. I'll have to look into it. :>