Personally i am a newbie to the Maya, i have been using it on and off (mostly off) for the last 6 months to a year. And am slowly catching on, i would recommend focusing on one style of modelling at first, getting good at that (polygonal) and then when you feel confident with that move onto nurbs and play around with subdiv a bit and see what either will give you in the way of benefits from each one. At least thats my two cents, since in the beginning i tried to focus on /everything/ since there is /so/ much to learn. But focusing on small things, or doing all the tutorials out there will help you out alot

Cheers!! ,
Imperator