When do babies start a good sleeping schedule?

I have a 3 month old little boy and I like to go places and get things done around the house etc… I am dying for him to get on a good sleeping schedule so I can plan my day a little better and finally finish things I start without worrying about my baby. When do babies start a good sleeping schedule? What can I do to help keep a strict sleeping schedule with out him crying when I put him down? Any suggestions would help tremendously! Thanks!