Time for some Mudboxin'.
Make a character--or six. We'll talk basic modeling this week, then get into texture in the next. Your finished character will be due on Thursday, February 26.
Start low poly and work on the big detail and silhouettes FIRST. Don't get into fine detail until you've established the silhouette and big forms. Here's a video on how to use the pose tools in Mudbox.
Here's the base mesh ol' Miles done made. With the basic grab, smooth, and bulge tools you should be able to get the big forms in pretty quickly. I used the base mesh above to hammer out roughs of two very different characters. You should have a distinctive low-poly sculpt within the first 30-60 minutes.