How do I go about auctioning autographed comics?

Hi there, I have about 20 books that were signed by artist Sam Glanzman. He did the pencils and inks for these war titles. Most of his signatures are on the splash page, some inside pages and cover pages. He passed away last July 2017. So how should I go about selling these? How can they be authenticated?

See his obit in The New York Times:
https://www.nytimes.com/2017/07/19/books/sam-glanzman-dead-comic-book-artist-of-combat.html

Most are between 2.5 - 5.0 raw grades, mostly independents, some DC titles.

That was an amazing obituary, well worth the read people!