When I started I knew zero anatomy, other than I knew I had limbs. I did like many do, and still do, and that was to try and cut corners by sculpting the whole entire body, at this point nothing looks good, ears, hands and feet are not even there, and can leave you feeling a little dissopointed in the slow progress.
I advice that you start with the human skull, work from the inside out as your need to understand the bones, and forms it makes under the skin. Look at drawings of the planes of the head, this will help you develop a simple basis for drawing and sculpting. Learn the fundimental muscles of the face, and how these contribute to expressions. The head alone is a good study, and from this alone your produce some stunning sculpts. Try not at this stage to think about detail. but more about form, dont be in a hurry to sub devide your mesh, make the best of lower levels first. When you can draw, and sculpt a skull, and head fleshed out, post your results for from constructive crit on these forums as you go.
Then after making tons of heads, move onto another body part, such as the torso, again start from inside out, rib cage, shapes forms, and then the origin and insertion of muscles, take note how they overlap, and what can be seen on the average human, take into account all levels of fat by looking at where the fat flanks are, sculpt and draw these. If you do it this way by the time you start doing whole bodys, your be producing seriouse sculpts.
Its takes time, im constantly refining, and always will be. Learn from the masters such as Zac Petroc, Ryan Kingling, Scott spencer, Scott Eaton, just to mention a few. Join 3D.SK download all types of bodys, male and female, fat and thin, get Eliot goldfinger anatomy for artist book, and most of all enjoy it, your learn faster that way.
That feeling you get when your working on somthing, when you start to see somthing looking solid at even early stages, this is what your after, you want to feel a wow! feeling, when your saying to your self “Now thats looking good”. If your feeling this often, then your progressing, and this time next year your look back on your old work and your beable to see every mistake with a smile.