I wouldn't normally post a link thread, but I know that loads of the regulars will find SexyLosers as funny as I do.
It's a web comic written by a Canadian guy living in Japan, and it's the funniest (and rudest) thing ever.
I'll ease you in gently with some comics on the theme of FMM threesomes...
From there I suggest you dive in to a thread you like the sound of in the index (it might be helpful if I tell you hentai is cartoon porn, and quite popular in Japan, I assume you all know what bukkake is already)
Be warned, there is something that will offend EVERYONE in there somewhere! - but it's all funny if yoy have an open mind. The qualty goes up the higher the number, but many of the threads need to be read from the start.