[sentence]。なお、[sentence] なお + [verb / i-adj]
なお at the start of a sentence adds a further point after the main one: "please note", "in addition". It is formal, written Japanese – notices, announcements, business email.
What follows なお is a side note: a condition, a deadline, where to ask. It is not the next step of an argument, which is what さらに introduces. In speech the everyday word is それから or あと.
These go beyond the sentence-opening なお.
Inside a sentence, なお means "still": a state goes on despite time passing or what was done. It is a written version of まだ, and いま今なお is "even now".
Before a word of degree, なお means "even more", a formal さらに or もっと.