Specs and info how to start my own roof truss plant.

Well firstly and most important you will need a shed load of CAPITAL $$$$$

You don't go online and in 1 short sentence get 'specs and info' on how to start any business (and if someone is in that business, why would they fork over all their hard work)?
You will have to spend weeks if not months just researching the demand, start up costs, local ordinances, federal and state taxes, lag time between raw materials and sales, and so on. Onanonanonanon...
Good luck.
When building and real estate was half of our burgeoning economy, roof trusses would have been a good venture. Right now, you could probably buy out a roof truss company for it's debts.

Not to discourage you or anything.