After 10 years in the pre-engineered metal building world as a project manager, quality manager, and lead estimator, I can say with confidence that insulation is one of the most difficult aspect of the project to deal with.
Condensation problems are always related to an incorrect insulation system being installed (or no insulation at all). The best thing to do is to get with an insulation supplier (Bay, Therm-All, Dominion), tell them what type of structure you are building and the zip code where it is being built, and they can give you a spreadsheet that shows the exact type and thickness of roof and wall insulation that is needed on your building. Tell them you want a building with no condensation issues. What you DONT want to do is go to Lowes and simply buy 6" of the cheap yellow stuff and think that will solve your insulation problems. It won't.
Also, if the insulation is un-faced (meaning there is no external vapor barrier), then you will have condensation issues. (Many people think they have roof leaks, when in fact, they ordered un-faced roof insulation and the condensation that drips down inside the building is often thought to be a roof leak. This is how I used to get the phone call "It hasn't rained in a month, yet my roof is leaking!!"). So, be sure your insulation order is for faced-insulation.
As far as interior ventilation, an independent engineer of record (foundation engineer) or perhaps even the city code official can give you guidance on how to properly ventilate the building. By using a combination of roof or wall mounted vents, 48" diameter cased-opening wall mounted fans, and even roof mounted ridge vents (single or multiple/continuous) with hand-chain operators can help you control the pressure inside the building.
