You may apply for this BED program via OUAC and the deadline is Dec 2nd every year. If missed, you will have to wait for another year.
This 8 months program contains two parts: on-campus classes and off-campus practicum; the latter will offer you some teaching experience in schools, which will definitely helps in your later job hunting.
On the other hand, if you have strong teaching background as well good language capability, this program is not mandatory.Before you apply your teaching license via OTC, you have to pass the ontario teacher qualification test and get good standing in TOEFL test.(TWE 5.5, TSE 55).