i. One of the most confusing issues in writing, is that a “line break” is also considered a scene break or point of view (POV) switch.
An author should either use an extra double space (the ONLY time when this is acceptable) or a single or double hash mark (“#”), against the left margin (or centred) to indicate a line break.
For example:
‘Being a gentleman, I give you the advantage of making the next move.’
#
Seated in one of the many Italian restaurants the mall had to offer, Josephine gazed
ii. On the last page there should be an indication that this is actually the end of the story.
Either “# # # # #” or “The End” (without the speech-marks of course) is most popular.
iii. Hyphenation should be turned off (even though it appears in the printed form).
iv. There should be two spaces after a full stop. This is less of a ‘must-do’ and more of a ‘good-if-you-do.’
v. “Punctuation always goes inside quotation marks.”
vi. Em-dashes should be shown as two hyphens — like so –. If your word processor auto-corrects these to a – instead, you can turn this feature off. If you can’t turn it off, ce’st la vie.
vii. Your spell-checker should be set for your target market – US for US publications (or agents) and UK for UK publishers etc.
a writing blog 
Argh. I recently trained myself to leave only one space at the end of each sentence after reading it was old fashioned and unnecessary to use two. Is that what you mean by a full stop?
In business terms, two spaces is seen as old-fashioned. It was something typists were trained to do back in the days when people didn’t have PCs. In terms of manuscripts, I’ve seen both a single space and a double space mentioned after a sentence has ended but more often a double space. Will it make or break a book sale? Not at all. As long as you’re consistent, it won’t be an issue.