No two UDS's are the same. They're all built a little differently with different materials. The one thing they have in common is that they take about a half dozen cooks to settle down and get figured out.
As suggested read the UDS Thread. At least go back a few pages and start following it. The learning curve is steep and you'll catch on fast.
As also stated, catch the temps on the way up. It happpens fast. Sart your coals and PUT THE LID ON. Start shutting down your intakes as you approach your desired temp. For me, one 3/4" intake open with approx 2" exhaust will run in the 225 range.
A good digital thermometer is worth is weight in gold. Check out the ET-732. It has changed the way I BBQ.