Hey guys, this is my first model in blender, i was trying to make a futuristic helicopter-ish thing…but,since im completely new to modelling, can you guys take a look at the model, and help me out, you know, fix the tiny imperfections, make some edges smooth, while keeping others sharp, and how to seperate objects from models…i know its a lot to ask, but, come on guys…humble request from one blenderhead to another…
only two things i notice:
try to stay away from triangles, and the other thing:
this dosnt exactly line up =P not a big deal, but just something i noticed…
Overall… Outstanding job! that will subsurf nicely and turn out looking good 
EDIT: much better than my first model… im jealous 
lol…thanks…btw, the rotors arnt meant to line up since they sorta rotate, and how do i fix the triangles? do i delete the verts? also, like in some models of cars, there are parts that are relatively sharp, like the bonnet and others that are rounded like the windshield, how do i achive that, because the smooth modifier or the set smooth option just smooths the entire thing out…not really giving the effect i needed…thanks again!
You can delete edges and then make the faces that are not triangles. If you add some subsurf modifier to your model and then set smooth, you can see in the turbines some problems that you must fix or create new turbines.
From the file i will upload with this message you can see the problem and how it come into the meshes.
The problem is in the object normals if you have that kind of faces in your object - blender does not know is the normal inside or outside of the object and then the edge where next face is normals outside and neightbour face is normals inside looks like that kind of black line. So you must find out some other way to create what ever youre doing…
normalsproblem.blend (128 KB)
