Ok, then. If you have the I-6 (4.0 Litre) engine, you'll have the AW-4. If you have a 4-cyl (or a diesel if you're outside the United States), you'll have some other transmission that I don't personally know much about.
For the AW4, here's a couple of ideas:
1. Fluid level and condition. If it's not red and clear, you're probably going to want to have the fluid changed.
2. TCU (transmission control computer). Located at the bottom of the dash below the glove box on U.S. models, check this to ensure that all electrical connections are tight. Also check for a blown fuse (I've never looked for this fuse personally, so I don't know whether the TCU fuse is on the TCU, in the main fuse block on the driver's side, or under the hood - got a service manual of some sort, like Chilton's/Haynes/Jeep FSM?)
3. TPS. Have you been spraying water around under the hood or been blasting through water lately? If so, track down a manual and look for how to check out the TPS (Throttle Position Sensor).
Hopefully this will get you started.
Good luck.
Rob