Larry_g and Deltarat speak words of wisdom .... consider having it erected.
There are many pole barn companies out there that sell a complete pole barn package and do the erection on your site with their crew. You should definitely check them out before you undertake the job of doing it all yourself.
They can show up at your site on Monday morning with a truck load of material and tools and when they drive away on Thursday or Friday you have a complete building (or as much of one as you want). They have everything pre-cut and they know what they are doing.
You will spend countless hours pondering how to do some simple task, spend lots of $$ on renting equipment, hours messing around with getting concrete deliveries scheduled, hours squabbling with the wife about where and how you are spending all of your free time, and who knows how many cases of beer for your buddies that will lend you a hand. Then, 6 months later you'll have your barn up vs. having your barn in one week from the pros.
This is not to say you can't do it yourself and maybe that's the way it works best for you, but give this lots of thought ....