Well, thankfully there is this:
https://steemit.com/steemit/@thecryptofiend/the-missing-faq-a-beginners-guide-to-using-steemit

and of course this:
https://steemit.com/welcome

These are shown in the user's home page 'blog' section, below "Looks like you haven't posted anything yet."

Agree some useful pointers could be emailed out upon successful account creation. I think there's a large learning curve for Steem/Steemit, particularly with the jargon that newcomers need to learn and get used to.