Hi - think our paths have crossed before on Primary Ed?
In what context are you writing, and why does it need to be more complex? If it's for publication, then these days different contexts will probably use different standards of English. So tabloid newspapers will be quite informal, even breaking 'rules'. Whereas The Times will (hopefully) be more accurate and observant of the correct rules.
If it's for on-line use, then personally I think that can be less formal again. I don't normally use 'text-speak' and sometimes do some abbreviation, then think: No, that looks horrid, and put it back in full. Also I sometimes just use Italic, or Italic+Bold, to indicate something is a quote within on-line things (assuming it's a situation that accepts such formatting.) [Now, there is a case in point: I'm not certain whether the 'full stop' after 'formatting' should be INSIDE the bracket, or after it. I believe UK do it inside, US favour outside - but I wouldn't risk any money on it.]
I don't know any websites, but love Lynne Truss' book, 'Eats, Shoots and Leaves'. David Crystal books are highly regarded too.
And Quotation Marks can be used differently from dialogue Speech Marks I believe.
I'm sure all this has been debated on Primary Ed within the last six months or so.