How to make a camera rotate on the spot? what I need to do is so simple, it seems, I can't find anyone who has made a tutorial on it, and as such, I am quite stuck, as I'm new to blender. 

What I need to do is rotate my camera 360 degrees on the spot about the X-axis as an animation (not just rotate it and move it about in 3D view, I know how to do that :P). The goal of this is that my camera is in a circular room-like environment, and I want an animation of the camera getting a complete look at every bit of the wall, not sure if that's relevant. 

First time posting, any help is very much appreciated :-).
Select your camera
Set a Keyframe by pressing I and selecting Rotation
Then move some frames forward (by clicking in the Timeline at the bottom)
Now rotate the camera by pressing R+X+3+6+0 and apply by pressing Enter 
(Press X twice if you want to rotate around a local axis instead)
Set another keyframe like in step 2


That's all. Note that the movement won't be linear by default. If you want a linear movement instead, you need to change the interpolation mode of the keyframes. For that, you can have a look at the second part of this answer.
Hope it helps :)