Projection is a massive subject with so many variables.
The main task (quality wise) is to keep re-sizing to a minimum. Find out what your project spits out and make sure that you input that into it.
So, if you shot in HDV and the projector shows HD, then ideally you would want to input HD into it. Depending what "input sockets" your projector has, you can either play it from tape, blueray or from a media player.