Atlas Comics (not to be confused with Atlas/Seaboard) is the company that spanned the time between Martin Goodman’s Timely Comics and the more familiar Marvel Comics.
Timely’s last comics was Captain America Comics #75 (Feb. 1950). The familiar 1950’s Atlas Globe then appeared and this was the overarching corporate entity for Goodman’s comic book publishing arm. The Atlas of the 1950’s tended to follow hot trends.
Atlas titles continue to be sought after by collectors, but for the most part have never really hit the big time like their predecessor Timely and eventually Marvel. One of the best resources for Atlas Comics is Atlas Tales. The site collects tons of information about the titles, characters, writers and artists that made this company tick. There’s also a cover collection.
If you are looking for Atlas comics values, the Overstreet Comic Book Price Guide remains an important price resource, and also contains a lot of research information.