I discovered something great earlier this week - this blog.
So far there is only one post on it, but damn, what a post! - 31 huge scans of J.C. Leyendecker Saturday Evening Post covers. They were posted back on August 2 and there's been no new activity since, but I hope we'll see more eventually. In the meantime, if you can tear yourself away from the sheer awesomeness that is the Leyendecker blog, be sure to check out these essays at the always excellent Illustration Art Blog.