As you have maybe noticed on my tutorial the Nurbs are limited to 16 isoparms in each U and V section, this means the the actual lines..

You can also import polygons, same limit there 16.

You can go higher, but you loose the form of your creation in SL.

For understanding the Maya UI (User Interface) i suggest first following some basic tutorials on Simply Maya, then when you understand the tools you can start creating your own stuff.

Learn first of Polygons, then with the tutorial i made you can follow it much easier.

Have fun.