Sandy,
This is a good start. Don't be afraid to post your work and ask for suggestions. Asking questions is how you learn. I ask questions all the time
! Steven has given some wonderful advice and I wanted to add a little information. What struck me first were the proportions (head, hands, upperbody length). An excellent book is "Drawing on the Right Side of the Brain." If you are beyond that book, "The Artist's Complete Guide to Facial Expressions," is another excellent book. Hope this helps, Renee