Final checks
Once the belt and platter are fitted and the power and speed controller are connected, you should to a final check that the platter is level when a record is in place.
If you have a stroboscopic disc and light, you should check the two speeds and adjust with the trim pots if necessary.  The speeds will drift over time, but you only need to check every few months rather than daily.
If you have a test disc, this will be your first opportunity to check the cartridge connections and adjust the anti-skate of your arm.