A friend of ours loves to hike and camp with his family and is a HUGE fan of the national park system. He started a blog fairly recently that talks about his family's adventures and has info on the national parks and tips based on his experiences. Check it out here:
http://www.roadtripdad.net/
Disclaimer: I have no affiliation with the blog. To the best of my knowledge, it is not any kind of commercial enterprise. He runs it purely for the love of adventure and to encourage other families to initiate adventures of their own.