I started when i was ~13 years old, max 2.5 (now we are at 7), i modelled some crap things, but after a while i got frustrated. A year later i bought a book and got hold of an new version, i started a Dutch 3d online community, and my skills grew.
http://www.cgtalk.com/showthread.php?t=21263
Is a big tutorials list.
Also, modeling something according to some pictures is the same as drawing a portray of someone, although not entirely the same. The 3d package is just a tool, just like a pencil and a paper sheet.