Finishing the basement - Exhaust questions/advice needed

[Buckeye Jack]

The basement is all framed in, I think I've got everything the way I want it. This will be the rec room. The pool table will be moved in as soon as its finished, and I'm already looking at Poker tables.

Currently with where I am putting the door closing it off from the rest of the house, it won't have a air return. There is a good sized window above ground (split level). There is a place to put an air return in with no problems. Do I want to do this? I have read of some sealing off their air returns so smoke doesn't filter through the whole house.

Also, what do you guys suggest for an exhaust? How big? I really don't know a whole lot about all of this, so this is a learning experience for me. I was considering putting one in like the back of the room, like the ones you used to find in kitchens, a pull chain opens the flap on the outside and starts the fan.

If need be, I could always put an ioinzer down their eventually. Any suggestions are appreciated.