Here's some useful stuff, CaesarCalad:
1. Specials (W) -> Inset Faces (N)
2. Knife Tool (K)
3. Loop Cut (Ctrl+R)
4. Extrude (E)
5. Scale along normals (Alt+S)
6. 3D cursor (more complex than just one keypress)
The first item is very useful for taking a complex region and giving it a near-uniform border of faces, from which you can extrude the interior region either out or in. I use this a lot to make recessed greeble portions. #2 is for when you need a shape to appear somewhere but manually inserting the vertices necessary would be a pain in the ass. So what you do is press k, and then click wherever you want a new vertex to appear. It automatically snaps to nearby edges and vertices, but can also operate on faces as well. Sometimes it does not work, and so you may have to fiddle with the base geometry before it'll take. #3 is for cutting a large segment of parallel edges in roughly the same place. This is useful for creating detail rings and for adding new vertices to work with. #4 I think you've got the hang of. #5 is for when you have a complex surface that needs to be extruded, but doing so with normal scaling would produce ugly results. Basically, what this does is scale all the selected vertices along their vertex normal. Play around with it a bit and you'll get the hang of it.
The last item here is a pretty important one. The 3D cursor allows you to define a new origin from which to apply any transformation, rotation or scaling operation. It is accessed from the 3D view. In the lower screen header, two roll-out menus to the right of the Mode menu, there's going to be a menu with two overlapping spheres and a blue dot in the center. These are all the different ways you can apply a transformation. The 3D cursor is the one with the reticule-like symbol. The 3D cursor can be quickly manipulated using Shift+S. If you snap the cursor to a selection, your transforms will treat the center of that selection as the center of the transform. So say you need to adjust the location of a vertex on a face that is not perpendicular to any of the global axes, you can select a vertex near it, snap to that vertex, and then scale towards and away from that vertex. I use this mostly to clean up a set of inset faces when the internal algorithm does stupid.
Edit: Also forgot to mention the transform orientation menu, which is the next roll-out to the right, after all of the buttons controlling the manipulator widget. This lets you define how a transform orients itself, and you can choose either Global, Local or Normal. Global means that X, Y and Z axes are taken from the world of the object. Local takes these coordinates from the object's rotation, so if you spun it about, moving along the Z axis would move upwards with respect to the object's own 'up' direction. The most useful of all of these is Normal, however. It lets you transform faces with respect to their current orientation with relative ease, and the direction the Z arrow points serves to warn you if you have any inverted normals. To tell a transform to lock to one of these settings, press the axis you want to lock twice. That'll move the lock from the global lock to the one you've defined in the transform orientation menu. Press a 3rd time to release the lock.
