Are you reading Written By, the magazine published by the Writers Guild of America? You should. It's a real good magazine and any aspiring writer who isn't reading every issue is missing a valuable resource. So is anyone who just wants to know more about the making of television shows and movies.
As a member, I get every issue in the mail but if I didn't, I'd pay. I think it's available on some newsstands and non-members can subscribe. Better still (and cheaper), you can read it or download it as a PDF over on this page.
The current issue is the February/March one with Greta Gerwig on the cover. There's a nice tribute to our friend Len Wein in it and I also enjoyed an article by Richard Stayton, who investigated the claim that William Goldman did not write 90% of the movie, All the President's Men. SPOILER ALERT: He says it isn't so. And there's plenty of other material in there you'll enjoy.