I do some BBQ smoking and have a couple of cookers. But I take it you want to make something like this
http://cowgirlscountry.blogspot.com/...mokehouse.html
She does a great blog and is a great person, very active in several BBQ and cooking forums.
Look into the smoker build section here. In fact the whole place is a great resource for all things smoking and BBQ.
http://www.smokingmeatforums.com/f/