Here are some of my favorite sites for learning about eclipses (including the upcoming Great American Eclipse!):
- Mr. Eclipse (the guy NASA uses)
- NASA Eclipse Web Site
- eclipse2017.org (make sure to check out the AMAZINGÂ interactive Google map!)
- timeanddate.com (and their eclipse list)
- Of course, one can certainly use the Wikipedia article on Eclipses (you can also go specifically to lunar and solar)
- One of my favorite astronomer-bloggers, Phil Plait (the “Bad Astronomer”) has a nice article with some good diagrams and pictures