how would I go about doing this I got a rebuilt 400 sbc but wanna give it more power.  The bottom end can handle it so can the Transmission.  Just looking for some advise.  

We need a little more than two sentences to give you advice.

Doing this? What do you mean?  

what kind of car are you putting it in?  you will probably have to custom fabricate the entire package unless you are putting it in a common car that may have a kit for it.  gib is right nobody can answer your question with the info you have provided.  

Sorry that was a little vague.I wanna turbocharge or even twin turbo my 400 small block I have know idea were to start.What are the best ways to hook up the turbo(s) and who should I get turbos from? Ill be doing more towing for now on and want the extra power.  Also for what im using my truck for (hauling and towing) would a supercharger work better for me or is turbo the right choice?  

Its in a 82 chevy C10 Truck  

A dedicated turbo build is way too extravagant for a tow rig.

Are you really willing to put more than two grand into a power adder alone? A 400 small Chevy will pull a very heavy load without forced induction.  

the first question you need to answer is the one that gib asked.  be true to yourself, "you don't got to lie to kick it".  do you want to spend $3000.00- 6000.00 on this truck for your kit because regardless of which system is best for your app.  your are looking at this type of pricetag for parts alone.

but asa far as your question goes, a turbo is not what you need turbos have to spool up before they even make power and a centrifugal supercharger is essentially the same way, although by different means.

if you are really serious about this question then what would be best for you is a roots blower.  a roots blower pretty much starts making power at idle and nothing else does that and if you are looking for power to tow with then you need low rpm torque.  this answerrs your question but the truth is why in the wold would you want to spend that much time and money on a work truck when your motor alone will do what you need it to do?  a hot rod is one thing but...  

A roots blower looks great because it will make a lot of boost down low, but the fact that it's incredibly inefficient and there isn't a very practical way to have an intercooler makes it a little questionable for a tow rig.

Towing means rpms at 3500 max, peak horsepower could be 4800 rpm and who would care? A lot of boost at the low-end is going to mean a drastic loss of efficiency and economy, a mini-blower is going to ask the question whether or not you should have a blower sticking out the hood since the engine won't need to make any top end power anyway.