Along with these I'd recommend Sankaku Channel. Lots of tags, often links to sources (I discovered Pixiv this way), the auto paging...
Unfortunately, for some reason lately they've started to add a shitload of new pics every day, in the order of tens of thousands. It's like no one takes care of submissions anymore. Before you think it's a good thing, know there are a lot of duplicates and badly tagged pics now, apparently you can't go beyond page 1000, and in general any good image can potentially drown among worse ones. I wish they'd go back to the 500~1000 new pics a day of before.
Still, give it a try if you also search for "safe" pics along with the H one.
