I love that Reddit. I use it to practice my websearch skills. When I have some knowledge about something I know what words to use, so going to that subreddit gives me a bunch of stuff where I have no knowledge at all, and I need to learn the right words to use.
http://www.reddit.com/r/whatisthisthing/
There are also these -
http://www.reddit.com/r/coffee/
http://www.reddit.com/r/dataisbeautiful/
http://www.reddit.com/r/chemicalreactiongifs/
There's also /r/startups, but it's plain boring.