Depends on what type of sausage you're asking about: Fresh or Cured/Pre-Cooked.
I'm guessing you're talking fresh, with no cure in it. I typically smoke fresh sausage at 250* - 270* for about a 1 to 1.5 hours. You need to get it the internal temp to 155* to 165* (depending on who you ask). I throw it on after the brisket or butts come off the smoker and into the cooler for resting, so the wood is what is ever in the smoker already - usually either hickory or oak. After it comes off the smoker, let it rest for 5 to 10 mins and go.
Proudly Smoking on a UDS, PBC &
Accidental Winner of the 2012 "Saucy" Throwdown.