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 everywhere)