Also, for the scaling, I'd recommend figuring out which is your X, Y, and Z axis in relations to the model, then either taking a picture of yourself in the same relation, and measuring the dimension you need.
For example, you take a full body picture, and you stand say 5 feet, 10 inches tall (for sake of making everything hard) and you import that into inventor, or some other CAD program that will give you actual dimensions.
In inventor (or choice of program) say it says the picture is 8 inches top to bottom, of that, you take up 7.5 inches of that picture.
Set 7.5 to equal 5'10 (70 inches), which will give you the scale of 9.333. (70/7.5) So from that, say your head on the picture measures 0.75 inches across. Multiple that by your scale (9.333) to get 6.99975 or about 7 inches. To double check, have someone use a measuring tape or calipers (if you're feeling adventurous). If it's a little bit bigger, slowly adjust the scale of that part until it's the correct size. Say your head is actually 7.5 inches across. You can take that info and should be able to stick it right into PD (after converting it to mm) and then your part is scaled. Rinse and repeat!
