A question about home canning!?

I got a whole ton of neat stuff for canning this Christmas. A pressure canner, a dutch oven, the jars and extra lids. I had to go get a can lifter and a few other things today. Do I really need the rack that separates the jars while they are processing? Can I use the rack in the pressure canner or the dutch oven? I am a very lost beginner in the world of canning. Please help!!!! Also, any other tips or suggestions about canning would be great!