For the porn:
There should be classes in how to use this thing, but some helpful pages are:
Some Notable Collections there:
Literotica, lots and lots and lots of user provided erotic stories, terrible non-intuitive interface,
almost no search function, very commercial (lots of adds, but as far as I know, no harmful ones).
There are a bunch of good stories there that aren't also posted on SOL and ASSTR.
AD WARNING: CONTENT WARNING!
This site's been around a while and there's a ton of really down and dirty stories there,
but it's run terribly since text is not the main business and it has changed hand many times over the years.
That said there's stuff her you will find nowhere else, if you have the stomach for it.