Affordable and straightfoward

iTTT Online TEFL Course is good. It covers most subjects necessary for someone to be a TEFL Teacher and it's based on a specific TEFL methodology - ESA -, although it also mentions other ones. The course is pretty straightfoward, easy to comprehend and very affordable. Being an online course, it's possible to study at our own pace (within a certain timeframe, of course). The one I got has tutor support and video lessons, which was great. I'd recommend it.