My advice (and this is only my advice) is that if you are intent on learning Maya's nurb's start with a modeler that does nurb's properly and has a proper tool set so you can learn the proper work flows and what to expect when tools work correctly. Tools that will give you proper error messages when you do things wrong. So when you come to Maya and stuff does not work and you get NO indication why you'll have an idea of what might cause things to fail.

You will still pull your hair out but at least you have a better idea of the proper way attack a NURB's model. As it is now you are guessing at how to do it AND you are going to be fighting the Maya crappy and unpredictable tool set so that even if you GUESS the right way to do it Maya will still not produce a proper result and you'll never know if you did it right or if Maya is just punking you!