I always find My Comic Shop's website to be a pretty good place to go look up issues and by month. It always blows me a way when you say look at a month from 1962 and see how few comics were published that month. I don't doubt that their database might be missing a few comics, but it definitely would have most of the major publishers.
Ironic thing was that even though comics were not at their biggest boom then, they still sold boatloads more than they do now and I swear there are more issues published in a week some times than a whole month back then.
Kinda weird to think that considering people say comics are dying that there are just way, way more comic books published every month now than really ever before.