One space after a full stop is fine. No need to get anal about it.

Putting a space after a period or comma makes your writing easier to read. As for putting two spaces after a period, that was the accepted practice during the days of typewriters, but now with computers and proportional fonts that adjust the spacing based on the size of the character typed, two spaces aren't necessary. http://www.quickanddirtytips.com/education/grammar/how-many-spaces-after-a-period?page=1

You should space once after a comma and twice after a period (full stop) that is used to end a sentence. There is no space after a period used in the middle of an abbreviation such as p.s. Note that most computer provide the larger space after a period at the end of a sentence.

Great question! There's actually a lively debate about spacing after periods. The short answer is that a space is needed to make the meaning clear--we put spaces between different words, and that doesn't change because a comma or a period is being used. A long time ago, printers would use an extra space between sentences, and when I was in school I was taught to use two spaces after a period and one space after a comma. Now, it's okay to just use one space after a period. It was just something people did traditionally because printers did it and it was what people were used to reading. So, in reality, there should be TWO spaces after a period!

in fact, they are spaces between words