Easy does it. Aligning the gears
Its very important to have the gears mesh properly with each other. If they are too tight there is a good chance that they will bind and not turn smoothly. Too loose and they could skip or have too much 'play' in the system. This can result in drawings that aren't as smooth as they should be.
If the gears seem to be stuck then take them off and inspect them. Don't force them. They should turn easily. A new user sent this picture of a gear that was aligned too tightly and then turned way too hard. Lighten up!
Changing the turntable
The turntable can be quite hard to remove at first. It will loosen up over time. The easiest way to remove the turntable is to place your palms on the sides of the turntable and rotate your hands to lift up. This works better than trying to pry the turntable off with your fingers.
Drive Screws
A backer found using the 2-1/2 inch drive screw to be easier than the 2 inch screw. By adding more bearings he used them as a handle to turn the drive screw. He also found it easier to add a separate gear to use as a drive gear.