First off I would say it's best remove the membrane like pork ribs. Second make sure you give them time to cook. After I cleaned them up, I patted them dry and I used a light coating of mustard and horseradish. Then threw down a basic rub. I didn't get too fancy with the flavor - Salt, pepper, garlic powder, paprika, and a little bit of thyme.
The last rack of full beef ribs I smoked were cooked for 5 hours at 225/250 no foil, then 1.5hrs to 2hrs foiled and .5hrs to finish them with some sauce. These type of ribs definitely need time for the fat to render so take your time.
That's just my .2 - Good luck!