1. Everyone has talked temperature, from a minimum of 250 to 300. I agree, and find that sweet spot that your smoker likes; dont arbitrarily force any one temperature at the sacrifice of sweet blue... 225 is frankly too low for ribs IMHO.
2. On the above, temperature is measured on the cooking surface, and NOT on the external mounted thermometer. The external ones are notoriously off, some as much as 60 degrees. Heaven forbid (and this happened to me) try to cook at 225 using the external thermometer only to find out that the surface cooking temperature was more like 190; this makes extremely sucky BBQ.
3. Foil, dont foil. That's a huge argument to some. I do and I'm not ashamed a bit. I foil on mine right at 1.5 hours mainly to limit the amount of smoke, but this is how I like my ribs. When I foil, right before I seal up the foil, I spritz them heavily.
4. Depending on your temperature is how long you cook 'em. The bend test is time honored and proven. I like mine ever-so-slighly more done than that, where they might pull apart if I bend them... Cook them to the texture you prefer.
5. Sauce, be careful when applying sauce. Know that nothing absorbs smoke better than sauce... Mind you, I prefer a Memphis Style no-sauce rib, but it's tough to get them to look heavenly that way, so I usually add sauce to some. I do so after the fact, after we've removed them from the smoker and let it sit for about 5 minutes before serving. The sauce is applied HOT HOT HOT, so it "sets up" all by itself...
6. EAT. PIG OUT. Get nasty with 'em. Like sex, you cant have too many, too much, or get too nasty. It's all gooooooood! *ZAP*