good tip is watch some tutorials. nurbs can be fine for very precise shapes since you can rebuild them and hop between high and low resolution patches. but at the same time nurbs can be crap because rebuilding surfaces doesn´t work so clean as one might expect after all. I use nurbs for architectural stuff or things like car bodies etc. nurbs suck (in my opinion) for organic modeling like humans and creatures. I used to exercise with nurbs for quite some month until I was able to say I had them under control. I do some industrial design modeling once in a while for a friend and there is simply no space for polygons in this area.
but I´d start with some tutorial if I where you. there is a good car modeling tut out from - I think his name was Darren Cromwoody or something like that. it´s from gnomon. this was what I started with.
everything starts and ends in the right place at the right time.