Are you wanting to hot smoke or cold smoke?
I just got my cold smoker going and it works GREAT!
Here's how I lucked into this one. I was at the Goodwill store (my FAVORITE shopping venue!) and came across a large metal cabinet about 2' X 3' X 3' with hinged doors front and back. Upon further investigation it became apparent that this was an old computer server cabinet. It was marked $7.00!!!
As it happens I had some bellies in the fridge curing that would be ready in a week or so and I immediately thought SMOKER!
I bought an electric hot plate from Wal-Mart for $8.00 and found an old 9"X9" pan in the barn for the smoke generator. Fill the pan with small hunks of apple wood from a tree I took down last year.
Got a pice of lumber and cut it to fit across one of the sets of mounting rails in the cabinet and added some hooks from the hardware store and I'm up and running.
The hot plate has a thermostatic control on it so it can be set so that the wood just smolders. I was able to keep the temp around 90-100F and still have a lot of good smoke.
I'm pretty stoked about this one. $20.00 invested and it's got a LOT of capacity.
Since I took these pictures I have closed off most of the ventilation holes in the cabinet with aluminum duct tape for better smoke retention. I also found a tall cylindrical stainless steel vessel ~6" diameter and~9" tall (at Goodwill) that I'm now using for the wood cannister. I can get about 5-6 hours of smoke with it before having to re-load.
I've also built a hot smoker for doing whole hogs but I don't have any pictures. I may try and take some and post them later.