Most professional writers punctuate differently than most amateurs do: amateurs usually limit themselves to periods and commas; professionals use all the marks—and use them in more ways!
Punctuating well gives your writing two important advantages:
This web site doesn't overwhelm you with all the rules of punctuation. Instead, it looks at the rules you probably need to know.
I suggest you go through the web site in order. Let's start with the
2007 by Edward P. Bailey