Ethan is the author of Responsive Web Design, and a pioneer in this field. In an earlier chapter, I did mention his book, and I can't emphasize enough that you have to go and give it a read.
Paul Irish is an American frontend engineer and developer advocate for Google Chrome. He is also recognized as an expert in web technologies such as HTML5 and CSS3.
I'd say that pretty much sums it up. He has a site aptly named http://www.paulirish.com, so it is pretty easy to find his work.
Another favorite developer of mine is Brad Frost. His website, http://www.bradfrost.com, is filled with wonderful advice and articles that are well worth a read. His topics of discussion include web design, writing, speaking, workshops, and consulting, just to name a few. His section on responsive design is filled with great patterns, resources, and news.
Inevitably, when you read, you will come across something that you don't fully understand. This is when you go looking for people who have been familiar with that subject for a long time. You'll notice that the community is very willing to help and assist. Asking questions on active forums often produces sufficient results.