I am assuming you have the one with 2 doors. If not it will be basically the same.
First you will need to check the thermometer for calibration. Simply remove it and place the probe tip in boiling water. Use tongs or something like that to hold it so you don't burn yourself. It should read 212f. If not sometimes you can hold a nut on the back of the therm with pliers and carefully turn the face/dial to get it to read the correct temp. Be very careful and make very small adjustments at a time. If you are not able to or not comfortable with making any adjustments, simply make a note of how much it is off and adjust accordingly.
Lighting the smoker and temps:
Open both doors before turning on the gas. I prefer to use a torch, but a standard long stick lighter works too, to light the flame. I will light my torch and place the flame next to the burner when I turn on the gas. I don't like to boom that can happen when gas builds up.........
close up the smoker and allow the temp to get to 250. Adjust the controler to maintain a steady temp. You will want to season your smoker before you cook in it. I would get it up to 300-350 and allow it to run for a couple hours, turn it down to 250 and place a few chunks of wood in the tray just above the burner and allow to smoke till the chunks are gone. The whole time you will want the top vent is open fully. This will allow for good air exchange. This is a good time to see how the temp control works and get a feel for it. When you add the chunks of wood it will be thick smoke, but should settle down after about 10 min.
There should be a vent towards the bottom of the smoker. That is used to allow O2 in for the burner to burn and the chunks to smolder. You don't want the chunks to light on fire. Wind can cause issues like temp spikes or flare ups in the wood chunks. If it is windy you may want to shield the bottom vents.
During your cook you will get temp variations. Don't panic! Make a little adjustment and wait at least 15-30 minutes before the next adjustment. We all want to look and see how the food is doing. It is not going anywhere. Allow it to do its thing and relax.......
Smoker setup and prep:
Light the smoker and get it up to the cook temp. Traditional low and slow is 225, I like to cook a little higher 250-275. There is a pan just above where the chunks go. That is the water pan. Your choice to cook with water or not, I don't. I wrap mine with foil and others will add other things for a heat sync. That is for later on when you get more comfortable.
Place the meat you are going to cook into the smoker, middle shelves. Start with something easy and cheap like chicken legs or thighs. They are forgiving and tasty......tons of recipes on SMF with and quick search. For chicken I would go hot cook at 275-300. Chicken can get a rubbery skin at lower temps.
Once the meat is in the smoker, add the chunks making sure the top vent is fully open. Add chunks as needed. Just because you don't see smoke, does not mean it is not getting flavor. as long as there are chunks smoldering you are getting flavor. Thick white smoke for a long time can cause the meat to get a bitter taste. That is why thin blue smoke is prefered for long cooks.
Seasoning and sauces:
Keep it simple. Too many people will crazy with seasonings, just ease into it. A simple salt, pepper, onion and garlic blend (SPOG) does a lot. Use a seasoning you are familiar with to start with while learning. After you get a few cooks under your belt and you are comfortable with running your smoker,nthen play with seasoning.
If you choose to add sauces to the meat. Wait till the end of the cook. The sugars can burn and cause a nasty bitter taste. Or just serve on the side....
Hope these help. Let me know if I can help more...