I am a newbie to smoking but I am an old hand at Dutch ovens.
A rule of thumb when seasoning your dutch oven is: If its still sticky it isn't done yet. Crank on a little more heat, give it some more time then test it again till it is no longer sticky.
Once done properly it will last and last.
Another good tip: When you put it away place a folded up paper towel between the lid and the oven this allows moisture to escape preventing rust.
You can actually cook outside on the bare ground by just putting briquettes underneath it , plus a few on the lid. If you dont have an oven with the 3 legs just place it on a couple of bricks with the charcoal underneath. Experiment with the briquettes and soon you can actually get quite accurate with the temperatures. Every 1/2 hour or so Lift the Oven by the handle and turn it 1/4 of the way round then turn the lid back 1/4 of a turn. This will help avoid hot spots in your food.
For roasting things The rule of thirds is use 6 coals underneath and 12 on top or put another way use 1/3 of the coals underneath and 3/2 of them on top. If you find this is too hot as it might be on a hot day with no wind subtract some of the coals. A lot of recipes will suggest how many coals are required for that particular dish.
When at a campground I find it is best to dig a hole 1 1/2 times as round as your oven and about 6-8 inches deep. This makes a good wind break. Pile the removed dirt from the hole upwind to further break the wind. I usually also will place a log or two on the upwind side. It makes your coals last longer and burn hotter.
Lodge makes very good DOs in my opinion. Cabelas are not bad either. Lodge will sell you an oven with your name cast right into the lid of the oven, way cool.