where you can find a lot of information:
by Advanced Energy.
A tip: check you local building code.
Strangely, some building codes do not allow crawl space encapsulation, and some only allow it under certain specifications.
An please beware!. Be really careful if you have combustion appliances in the crawl space!!!
Those appliances need a consistent air flow to work and you don't want to depressurize the space around them. If you are not completely, 100% sure about what you are doing, please get a professional to do it.