Since you plan on smoking in it your most valuable tools are these:
Weber Charcoal Chimney This will light your charcoal quickly and easily without ruining the taste by adding lighter fluid.
Grill Brush This will keep your grates from getting nasty. Use this at the start of your cook, after the grill is preheated but before you put the food on.
Wireless Thermometer
1 or
2. The first one is cheap, uses bluetooth to display on your phone, and graphs your temperature so you can see how your actions effect the temperature. I find this very helpful for learning. The second has two probes so one can go in the food in addition to the one you put on your grate level for smoker temperature. It also has a range that is twice as long if you plan on being farther from your grill.
For your first smoke I can't recommend a pork butt highly enough. They are the most forgiving and they are cheap and tasty.
I also recommend you use the
Snake/Fuse Method (scroll until you see "
For long cooks.") Eventually you might want to upgrade to the
Slow 'N Sear like I did but you can still get good results without it.
Don't use the lid thermometer since it'll give a very different reading then at grate level. If you insist on using it for the first cook to see if you enjoy the hobby before you drop another $40-$60 know it'll read higher so I'd shoot for 300*F on it. It's usually between 25*F and 75*F higher than grate level so this would hopefully put you between 225*F and 275*F depending on where the lid thermometer is compared to what part of the fuse is currently lit. The nice thing about pork butt is it can take a wide variety of temperatures and still turn out tasty. It's why it's great for a beginner before you have lots of practice maintaining temperatures where you want them.