Hey Candice!
There are a couple of spectacular books out there that you can pic up... which I will list in a moment
If you have the inspiration and are already a talented artist... Like you are, then that will help you out a lot. Sculpting is about seeing and observing mostly. It's how you translate what you already are seeing and or perceiving. I still don't have it all figured out but man what a difference having reference and the right tools can make. Magazines, other people's sculpts, books, live models, photos, web... The amount of research and material you can find are outstanding... just gotta pick it up and go to it m'lady because it is so addictive it's rediculous...
Now to the books
The holy grail of face/head/portrait sculpting
"Portrait Sculpting"
by Philippe and Charles Faraut (only available through their web site PCF studios...
"Modeling the figure in clay"
by Lucchesi
"Modeling the head in clay"
by Lucchesi (this is okay but not as cool as the portrait sculpting book
Any really good anatomy book you can land is also a plus...
These are my staples but then I try to reference the heck outta any sculpting attempt... If you weasle enough you can get people to pose for you and you can use those to reference the way the muscles flex and the way the skin covers them in that position...
Hope this helps a little... If I had any talent to back it up I'd be better suited to give advice
Keith