Check the frame to make sure it is solid. Take a look at the rear where the shackles mount to the frame. This can be a problem area. Also check the front where the steering box mounts to the frame.
Change all your fluids. This way you can make sure they're all clean and you know you have a good starting point. Check your vent lines to make sure they are all in place. Check the 4WD vacuum lines. Mine were bad. They are plastic and get brittle over the years. Especially where they run near the exhaust.
I just picked up my first Jeep this spring and love it!
Post some pics and we can give you some more ideas. Have fun and don't forget to wave.