Hi Billa, so here's the thing to get used to, when you have an area like this to surface:



If that's all one smooth surface making a kind of smooth "sheet" form without any sharp bends or transitions within it, then it's good for that to be made out of one single surface.

However, the piece you want to build is an extended form that has a simpler structure to it. you want to temporarily ignore the boundaries of the final result, instead you need to make relaxed boundaries of a larger extended surface like this:



Then the end edges are going to be formed by intersecting some of these broad extended sheets with each other, rather than drawing in all the edges and trying to construct surfaces directly to those end edges. The end edges are too irregular here to be used to directly construct a surface from, they need to be a trim boundary (formed by boolean or trim) on a larger underlying surface rather than directly being the edges of a constructed surface.

This concept of extended surfaces that intersect each other is one of the main differences between NURBS modeling and poly modeling.

There are some tips here for people coming from a poly modeling background, they may be helpful:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael