Okay, thoughts on that: (1) I can't speak for your community, SR is special so don't use it as an argument for these questions to be on topic
here. (2) Books are off topic on SR, (3) As for puzzling
sites, probably not. There was a debate about websites vs. webapps, and we ultimately decided that we want webapp recommendations, not website recs. See
meta.softwarerecs.stackexchange.com/a/219/46 for more info on that. (4) Games: Maybe, see (cont.)