Not bad for a first human, but yeah, disproportional in a few places. The first thing I notice is the pelvic area. Your character has a large lump on its front side, and a flat backside - looks like it's bum is on the front! The characters pectoral muscles look a bit too high, and a clavicle doesn't seem to exist. You would also probably benefit from making the lower ribs less noticeable, as they currently extrude from the torso rather rigidly.
But once again, very well done for a first attempt - just giving you some C&C to help make this model (and your skill as a modeler!) better
Hope to see more work soon!
Windows XP Pro x64 - ASUS P35 Platinum Mobo - nVidia GeForce 8800GTS 640MB GPU - Intel Core2 Duo E6750 @ 2.66GHz - 4GB DDR2 1066MHz RAM - Two Hanns-G HW194D Displays @ Duelview Configuration