Sourdough starter

Thought I would try my hand at making sourdough. I have looked at a couple of different recipes, and watched a couple of videos. Some make the starter by removing some and "feeding" it everyday. I found another which is set and forget. Make the starter from flour and water, cover and wait 2 - 3 weeks. Well today is day 3 of my starter. It has started to bubble and smell!!! I presume that this is what it is supposed to do.

Any sourdough makers out there that could give me a few pointers????