Tish, with the sweeter rubs and/or sauces, when smoking try as best you can to keep the temperatures under about 265, preferably in the 250 range. Otherwise sugars can burn.
With rubs, I suggest starting with a few over-the-counter ones before you go it alone. Note however that most are loaded with salt. I'm told that Simply Marvelous (above) are a bit lower on sodium than most. Another awesome starter rub would be Plowboy's Yardbird. The rub I make and compete with is similar in flavor to this only with less sodium.
With the sweeter sauces I highly suggest that you use them as a finishing sauce (ala. not grill it on there) and apply after smoking/grilling when hot. As earlier, this will prevent burning those sugars.
A very sweet and somewhat spicy sauce that we use as part of our sauces is Blues Hog Original.
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.