Please know that your first X number of cooks (X being somewhere between 2 to 15) has more to do with fire and smoke control than it does actually cooking. I know that probably sounds strange, but it's true. Focus on trying to hit and hold a temperature, and finding the temperature your smoker likes to hold. If that temperature is somewhere between 240 to 280, you're golden. Smoke, not billowy white, and not black. Sweet "thin" blue is desired. That also shows you have a very clean burning, usually small, but hot fire. With sweet blue you wont have creosote blackening your meat(s) either.
Understanding this (above), I start with the most forgiving meat of all of them, and that's a pork butt. Bone in, 8-10#. Use a simple rub.
Also, because your first few smokes are about learning how to manage and control your smoker, I've always suggested that you foil your butt after a few hours. The reason (for those who are against foiling) is this: Foiling helps reduce the potential negative happenings to your meat. If you have a flare up; it's less likely to burn or dry out your meat. If you get into an over-smokey situation, your meat is protected. And so on.... Me, I'd suggest foiling about that 3rd to 4th hour.
Hance - Lake Dogs Cooking Team - MiM/MBN/GBA CBJ and comp cook
Lake Sinclair, GA (strategically about an hour from darn near anywhere)
Started competing in chili cookoffs back in the 1990's and have competed in more than I care to count. I became a CBJ in MiM in 2005, then MBN and in GBA in 2010. I've probably judged 130+- BBQ comps (sanctioned and unsanctioned) over this time. That said, I really enjoy competing more than I enjoy judging, and hope to get back to doing 4 or 5 a year in the near future.