Yes 5-6 hours is about right. You can do the 3-2-1 method as per LUCC's link.
Here's what I do. A sort of modified 3-2-1. Instead of 3 hours for the first part, Cook them at 230f till you see about 1/4 inch pullback of the meat on the bones. That is a good indicator that they are ready for the 2 hours in foil with a few squirts of rum and apple juice. Get the heavy duty foil ( I get mine at cosco ) because regular foil likes to get holes in it which lets out the moisture.
For the last part you usually only have to do about 1/2 to 3/4 of an hour to firm up the ribs you will have ribs to die for..
I like apple, cherry, pecan, grape, or any fruit wood for ribs even hicory sometimes. Mesquite seems a bit too strong to me. I do like it on beef though. Hope your smoke is successful.
The best advice I can give you is DON"T PEEK! If your peeking your not cooking it takes the smoker about a 20 minutes to a 1/2 hour to recover every time you peek. Peek 3 times and you have added an hour or more to the smoke. Start them way early and when they are done double wrap in foil then into a cooler with some towels for packing will keep them hot till suppertime. Better if they are done too soon than too late.
If you are doing the 3 2 1 method or any variation thereof you do not need to mop in my opinion.
You can however just slam the ribs in at 230f and smoke them right thru till they are done ( about 5-6 hours ) moping about twice during that time to keep them moist. Don't mop for at least an hour and a half so the bark does not wash off. Apple juice and rum , apple juice and burbon , straight spiced rum etc all make good mops. My favorite is straight up orange brandy. Your milage may vary.
I couldn't find a good picture of pull back in my pics so I copied this link to Trashcan's recent post. Scroll down to the 7th picture for a really good example of pull back of the meat from the bones. Also check out his recipe for a pretty good rub that won't cost you and arm and a leg to produce. http://www.smokingmeatforums.com/for...threadid=78990
Smoke on Dude!