Overview: The website has a lot of links that one can use to follow into more detail about each linked word/subject. The author is an RN and it the website was reviewed by an MD and updated only a couple months ago.
Content: There are a lot of links with each subtitle. There is more to learn then just social development. It is very informative; also you can look at Spanish speaking sites.
Design: I think they could make it prettier with the links under the subtitles, and more information next to the links. But the website is easy to follow overall.