How much notice to tenant?

If you want your tenant to vacate the premises, a 30-day notice is standard.  That would be 30 days from from the date rent is next due.  However, depending on why you want the tenant to move the time frame may vary.  If it is you simply to put in a new tenant or the like, then the aforementioned 30 days is appropriate. If however, it is for non-payment of rent or for illegal activities, it could be substantially less than that; 3 days in some cases.  You did not specify.