Caching http resources for increasing page speed

I found there really interesting articles about caching http resources for page speed:

How To Optimize Your Site With HTTP Caching
http://betterexplained.com/articles/how-to-optimize-your-site-with-http-caching/

HTTP caching
https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching

Static Asset Caching Using Apache on Heroku
http://www.xyu.io/2013/08/static-asset-caching/