Camera Help

I want to get a camera going to move around the screen in a level. I've been looking through tutorials on NeHe for something like this, but I couldnt find anything. I know how to use the keys to move it forward and stuff like that, I just want to figure out how to use the mouse to rotate the camera. I know that the xposition will do the Y rotating for the camera, and the y position will control the X rotation. Im using OpenGL.

Also, most of the tutorials on NeHe just move and rotate the all of the objects. This may sound noobish, but thats not the best way to do it right? Like, rotating a camera is better? Can someone please explain this briefly?

I haven't worked with OpenGL in forever, but this is how I do it using DX to make the camera move around the world like a First Person Shooter (which includes moving the camera with the mouse):

Remember that OpenGL is using a right handed coordinatsystem, and DirectX is using a left handed though...