The incline press is a fairly standard lift, so I don't think that there is too much that needs to be said about this lift. I think this is a great lift for max effort and supplemental lifting. I think this is a great way to strengthen your shoulders, which is often what is holding people back on the bench press. I feel that this lift will help your strength on the bottom half of a bench press. So if you are weak off of your chest, you may want to try inclines.
The one coaching point that has helped me is to always bring the bar high on your chest. I see some people try to bring the bar low, and this makes this lift very awkward and puts undue stress on the shoulders. So when bringing the bar down, I always aim for my collarbone.
As a max effort lift, going to a 1-3RM is the norm. For supplemental work, 3-5 sets of 6-12 reps is common. If you are weak off your chest, I like using this lift as a supplemental lift.
Any grip can be used but have found that a medium grip (pinky on the rings) has always been the best. This allows for a lot of strenth in the shoulders while minimizing the stress on that joint. But it's all personal preference.
As far as what angle to place the bench, there is no right or wrong, just different. So feel free to adjust the angles if you have the opportunity.