What is this site's stance on Q and A style posts. For example, I have seen a lot of posts regarding confusion between codecs and containers, so I want to ask a question such as "What are codecs and containers and how are they used?" and then answer my own question. Is this a good idea/encouraged on this site?
Absolutely. You can either post it as a question that is also seeking other answers in addition to your own, or if you want it to be kind of an overall master answer that everyone edits, you can mark it as a Wiki question and then anyone will freely be able to edit it so that we can try to have a single community written answer that really goes in to excellent detail.
It isn't just permitted but even encouraged. Anything that will help other people find answers in the future is helpful.