Here's my Lessons Learned from
WSM's and other bullet smokers:
1. Don't expect temperature stability like electric smokers. If that's really important to you, there are after-market thermostatically controlled fans (for the bottom air feed point) that help after 30 minutes or so, but I think temp stability better than +/- 25F is over-rated, and after a few cooks, you'll learn how to achieve that via fuel arrangement and vent settings.
2. I like water in my water pan. It gives moister meat and helps temperature stability. Exception is high temp 20-minute cooks like burgers. (These are versatile machines.) However plenty of good cooks don't like the water. That's fine, but make sure you have SOMETHING that shields all your meat from any direct line-of-sight path to the hot coals/wood. Otherwise the added infrared heating (over the normal convective heating) will overcook part of your meal. And if you like a clean machine, cover that water bowl (or IR plate, like a pizza pan) with foil for faster clean-up.
3. Except for high temp cooks (e.g. burgers) you need your fuel to only slowly ignite so use something like the minion method. I high recommend a "chimney" to start your coals but I never use more than a half-chimney. I use a 1 pound steel coffee can, open both ends, in the middle with unlit coals (and some wood chunks) arranged radially around it, then pour in the hot coals, then pull out the can with channel locks...leaves a well-defined boundary to the fire to radially expand out into. Leave the vents wide open for 10 minutes to get everything up to temp, then close both way down. For cooks under 250F, it's amazing how little air flow you need. In cold weather, I put a large cardboard box around it (openings top and bottom) which conserves fuel, keeps the fire going, and prevents huge temp excursions which happen when your fire is close to going out and you have to compensate with a big vent change. (I use a box in summer too, unless guests are around, since it looks pretty funky.) If you just can't stomach the cardboard box idea, at least put some wind shielding on the upwind side.
4. for long cooks, you may need to open the side "door" to quickly add fuel or water, but remember these cookers are NOT for Lookie-Lou's. You need a "remote" thermometer in your meat, and that's your only diagnostic...you can't check for color, flex of meat, juiciness, etc...trust your machine. A wired one under $10 from Ikea work fine. A 2nd one monitoring internal cooker temp is useful too but the built-in dial thermometer is good enough. These are not set-and-forget pellet machines. Use a timer and check on your temps and general fire safety matters every 15-20 minutes. If you use more expensive, rf-based (true remote) thermometers on both cooker and internal meat temps you can go longer, but I'd never be more than a 20-second run from one of these. And always have a garden hose handy. I've never needed one, but have had a couple impressive flare-ups with other fuel-based smokers where I lost part of my meal and was glad I was at least prepared.
5. speaking of the side door, prepare some tubing and funnel in advance to add water...a simple funnel usually won't work. And for adding fuel (only needed for >4 hour cooks) I use a 3-foot section of steel rain gutter, prefilled with unlit fuel, that I can then tip up and quickly add to the charcoal pan. You really don't want to leave that door open more than a few seconds.
6. As far as fuel goes, there's plenty of opinions so search this forum. IMO just about any lump charcoal is better than about any briquettes! But sort out (or break up) the really big lumps or the questionable (lumber-type) lumps. Wood chunks for a little more smoke flavor place on top of coals are very common, although I prefer little smoke bombs (empty soda cans half filled with pellets) or a small cast iron pan filled with chips/pellets placed about half-way out on the fire. But frequently a charcoal-only smoke really hits the spot. See what you like. These are VERY versatile smokers and a great way to get into this hobby.