Glad you joined us rcpilot, congrats on the new Smoke Hollow and :welcome1: from North Dakota!
Your top vent on the back side should be the exhaust and this should be completely open whenever applying smoke. The bottom 2 vents are for controlling air/smoke flow, these you will just have to experiment with and the settings will normally differ pending outside temperature and wind direction.
Typically you leave the top vent open and adjust your temp by the lower vents. Use our search tool. I bet you'll get an answer for your specific model.
I You ve come to the best place for great information on smoking and many other types of cooking! Many friendly people here that love to help. Also make the search button your best friend. There are over a million post in this forum. That powerful information on a vast array of subjects right at your fingertips. Brian