You should research all the schools you are slightly interested in before applying to them. Otherwise it will be wasted time and money.
Typically, when you apply to Early Decision the schools will let you know if you are accepted, denied or deferred to regualr admission. The school I am applying to, UK, will let its Early Decision applicants know by Oct. 31. I don't know how early the other schools will let you know. You can find out by going to the school's website and looking around.