Drawing from life
Drawing from life is awesome!
Look for life drawing classes in your environment, or if they're not available; ask your friends to pose for you. Go have a drink in the city when the weather is nice, and sketch people passing by. There's nowhere you learn more about human anatomy than by observing and sketching real people. There's only one downside to this; dynamic poses are tricky, as it's hard for any model to hold a difficult pose for a long time.
And no... drawing (nearly) naked people in a drawing class isn't awkward. I