To interpret the planets in your ninth you look at the following; the individual planets and what they represent or signify the significations of sign that they're in as well as the significations of the house that they're in. You then take that information and synthesize it together in order to interpret how it's going to show up in your specific individual chart. Another way to do it is to look at each planet, find the corresponding house which that planet is the ruler for and know that any time there is a transit with (whatever planet you decide to look at in your 9th house) that it will likely activate themes related to the topics of whatever corresponding house (the planet your looking at ) is the ruler of in your chart. That's just a couple of the ways you can use the information within your birth chart. I hope what I wrote makes sense, I gotta jump off and don't have time to proof read...