After getting pretty depressed about the the whole affair and their emphasis on simply expressing ourselves, (we were more like a bunch of untutored chimpanzees with paint and paintbrushes than art students) I stopped going to classes.
But, I had to support myself and thus became an illustrator. I used photographs. Sniff.
Later in life I decided to go back to my first love- damn the abstract expressionists- full steam ahead. I did what I always did- used photographs to launch an anemic portrait career.
There were no ateliers then - I did not know what sight-size was- imprimatura, massing, you name it. I had photographs blown up, traced them, put a piece of plastic in top and matched the color to the photograph.
I thought I was FABULOUS- until I went to the Boston Museum and saw the Sargents, the Stuarts and the panoply of magnificent figurative work. I realized that I would have to learn how to draw and paint properly.
To cut to the chase- DO NOT run out and hire a model until you have your drawing down cold. Do not use color at first. Stick to monochrome. Really nail the basics. There are no shortcuts even though it may look like there are. Trust me. I wish I could run a knife through most every early piece I did from photos.
There are some excellent books on this- one is http://www.amazon.com/gp/product/0823006573/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=0823006581&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=05ZW0Q7DS43VPQKM7A6T
If you can go to an atelier or a decent school where they actually teach you the classic way. Even one year is worth it. Stay away from overpriced, overrated schools like the Rhode Island School of design where there is no instruction in this whatsoever. Students have to go to optional classes and pay for their own models.