Just another Hardwood Store Question

Tried searching for an answer to this but could not find anything conclusive. I would like to buy some rough sawn lumber because the price is much better, but also because I think it would be sort of an initiation to becoming a woodworker. So my question is this, if you buy rough sawn do you always have to let it sit to dry out for long periods of time or does it usually come dried already? I know you should let it acclimate for a little bit and give it a break during the milling process, but I'm talking like let it sit for months to dry out. Thanks in advance.