Permies.com – A lot of great permaculture related articles and the best permaculture related forum on the web.
Weston A. Price Foundation – Advocates eating clean, natural, raw food. Great resource for learning about traditional nutrition.
Toby Hemenway – Author of Gaia’s Garden: A Guide to Home-Scale Permaculture, 2nd Edition. His site also has a blog and some great videos.
Geoff Lawton – Offers an online Permaculture Design Course. His site also features a bunch of great videos on different permaculture subjects.