We receive quite a lot of questions from layman in evolutionary biology in this site that are sometimes difficult to answer just because there is way too much to say. Why don't human keep evolving? is a perfect example. I often want to give some pieces of information and link to a good source of information for them to get introductory knowledge in evolutionary biology.
Obviously nobody that ask a question on a Stack website want to read an answer of the kind You should read that book!
. It is often not really pleasant to read a book, it takes time and the OP that get this answer will likely just forget about their question.
What are the best online resources that offer a very introductory understanding in evolutionary biology?
Either a written course of videos such as Khan Academy videos would do (I haven't watched the evolutionary biology section of Khan Academy though and can't really judge of how good it is).