Recommended timeframe for waiting before sitting on bait?
The sign will tell you. If you have a game camera available, put it up as well. If there are LOTS of hogs in the area, you could be setting it in less than 48 hours.
How are you wanting to hunt them, bow, gun, stand, spot and stalk, riding around, etc....?
If you have a depredation permit to bait them, you can get a couple bags and simply ride the logging roads real slow and sprinkle corn over a large area. Then ride those roads again about an hour before dark and you should have pigs hitting it. Of course, be careful and make sure you don't shoot someone coming down the road toward you.
Basically, doing this will allow you to put a line of corn over a couple of miles (assuming large property) and if a pig crosses that line, they will turn and feed down it for a long way. Makes them easy to find. This method works great when gun hunting of course.