is it possible to record camera flybys andthen render them?
Yes it is. The camera is like any other object in that you can animate it using ipo curves.
This article shows the very basics of creating ipo curves using key frames. Try it with the camera. To show a preview, select the camera, press ctrl numpad 0 ( this will switch to camera view), then press alt a to start the animation in a 3D window.
To render an animation, go to the Scene buttons, change the output to where you want the file to show up, change the start and end frames, change the type (I recomend avi jpeg), quality, etc, and then hit the big “ANIM” button. Then wait. Depending on the power of your system and how detailed or long the animation is, I would recommend starting the animation before your go to sleep.
Look up render-baking if you want to speed up the rendering on objects that aren’t moving.