Robb Wolf's website, podcast and book, The Paleo Solution should be the first stop for folks who are looking to get major serious about the Paleo lifestyle.
Mark's Daily Apple is an amazing resource. His search box has information on topics ranging from artificial sweetener, to sunblock to canola oil. His site is easily searchable, and his advice easy to work into your daily life.
Richard Nikoley's blog is a completely irreverent. Free The Animal brings a raw and primal take on diet and lifestyle.
Melissa's McEwen's Hunt Gather Love is smart. Melissa provide a friendly, feminine face to some of the smart talkin' paleo folks.