RYNO,
Download the NCAA Transfer guide, and read it. Transfers from a 4 year school to another 4 year school are covered starting on page 20. The fact that the player attended a 2 year school first is basically not relevant to the transfer rules.
Generally, a baseball player can transfer to a D2 schol without sitting if this is his first 4 to 4 transfer.
For transfers into D3, sitting would only be necessary if the player were academically or athletically ineligible at the first 4 year school.
I don't know about NAIA schools.
Transfer guide