Online gallery on Haggin Mueseum, one of the largest holders of JC Leyendeckers original art
http://www.hagginmuseum.org/leyendecker/gallery.shtml
A new blog dedicated to this great artist
http://www.jcleyendecker.blogspot.com/
Also check out this recent post of James Gurney where he tells us about a letter leyendecker wrote to a student outlining his process.
http://www.gurneyjourney.blogspot.com/2010/09/leyendeckers-method.html