I drew this figure from one of the many views offered in "Art Models 4." This series of books is a boon to artists who want to draw figures but who cannot afford models or don't have access to them. "Art Models 4" contains many classic poses, some of them imitations of famous statues and characters. All the poses are fine-arts type which means that they are sedate, quiet, demure (despite being nude) and traditionally posed. Other "Art Models" books, especially the recently published number 7, have more action-oriented poses, since the publishers know that many fantasy or comics artists are using these books. The CD that comes with the book contains pictures of each model pose from many different angles. That way you get perspective and foreshortening to work with. Since it's on a CD, you see the image on the screen and can place it next to the drawing area in Photoshop or another drawing program. If you want to work on paper, you can print out the model images.
I'm trying to work with all-digital drawing and painting. This figure was drawn with Wacom stylus and tablet in Photoshop. I've done this type of digital drawing before, but have never been satisfied with my results. I kept the shading to a minimum because I was afraid of messing it up. It took me much longer to draw this (more than an hour) than it would if I were drawing in pencil. This means that I need to do many, many more digital drawings to get good at it. I have books on digital inking which will help me along.
Pin-up girls are not part of the "Art Models" series. Pin-ups are by their nature not "fine art" productions and so I find my pin-up girls elsewhere. In a pin-up, the girl looks out at you, the viewer, inviting you to have fun with her. She interacts with you, even if she's only an image. The "Art Models" in the formal books never look out at the viewer. This is obviously a choice the publishers made. I just have to keep drawing. I will be drawing figures on the iPad too (using a printout, perhaps) since it will soon be too cold to draw outside during my work break.