In many places in those threads it tells you double spaced. And NEVER NEVER EVER print on both sides of the page--paper quality should be that the letters of the page underneath don't show through.
You might want to subscribe to Writer's Digest, or buy a few how to books for beginners.
This is taken from my agent's web site, it is a good standard guide.
The following are standard manuscript preparation guidelines. Formatting your work to these specifications will make it easier for your book to be evaluated.
Margins: 1 inch all around.
Font: Courier or Courier New is preferred but we also like Franklin Gothic Book. 12 point always. Please note that Smart Quotes and other symbols may not print correctly in Courier, so you may have to turn off Smart Quotes if you are going to use plain Courier.
Italics: Never use italics. Instead, use an underline to indicate italics. This is because typesetters will not respond to italics, only to underlined words. Please note that the punctuation following a word to be set in italics should also be underlined.
Spelling: Preferred spellings may be found in Merriam-Webster's Collegiate Dictionary, 11th Ed. If your word processor has a spell-checker, please use it. Also, please set your grammar checker to on and be sure it checks for two spaces at the end of a sentence and punctuation inside quote marks.
Spacing: Double-spaced, always. There should never be a single space; there should also never be a triple space. If you want to insert a line space to indicate a change of viewpoint or a change of setting, or other break in the narrative, insert a centered pound sign (#) where the line space should be.
Justification: Left for all paragraph text. Chapter numbers can be centered, but please use the centering command. Do not tab over to center your chapter numbers.
Tabs: At the beginning of every paragraph. Some authors don’t bother to indent the first paragraph of a chapter. Please do.
You should never have more than one tab. It is strongly recommended that, during your final review of the manuscript, you set your word-processor to show all non-printing characters, e.g., paragraph marks, tabs, spaces, etc. This will help you to see if you have extra breaks, tabs, etc.
In Microsoft Word,
On the Tools menu, click Options, and then click the View tab.
Under Formatting marks, select the check boxes next to the characters you want to display.
Tip: To display all formatting marks, select the All check box instead of selecting each individual check box. You can also turn the All option on or off by clicking Show/Hide.
Chapter Breaks: Always start a new chapter on a new page. However, do not just hit return until you get to a new page. Use CTRL-Return or Insert Page Break to start a new page.
Header: Your page header should include the title of your work in the top left-hand corner and also your name, e.g., MY BOOK/Joe Smith/Draft #. We no longer recommend dating it, as it may take a while for your work to sell. The page number should go in the top right-hand corner. They should be in the same font as the body of your manuscript, but may be in a slightly smaller type size, e.g., 10 point.
AutoReplace: Microsoft Word has exceptional AutoFormat and AutoText features that are very useful for most business writing. However, some of these features are best turned off when writing a book. Do not allow the computer to replace two dashes (--) with a long dash (—). Do not allow the computer to replace three periods for ellipses (. . .) with a single character (…).
File: Many authors prefer to write chapters in separate files. This is useful for backing up chapters. However, when we ask for a manuscript, it must be consecutively numbered and when we ask for the file, we want one, single file containing the whole work, please.
Print-outs: Preferably laser, but in no event less than letter quality. If using a dot-matrix printer, please use a new ribbon. This goes even for “draft” manuscripts intended only for the company’s review. Please use a bright white paper intended for the type of printer you are using. Remember, this manuscript may be photocopied by the company several times and therefore should be on good enough paper to produce quality copies.
Shipping: Please box your manuscripts when shipping them, preferably in a hard box, not just a photocopy shop box. The Post Office provides hard Priority Mail boxes at no charge. Put your manuscript in a copy shop box and then into the Priority Mail box for maximum protection. This is to ensure that your materials do not get crushed and become unusable for submission or photocopying.
Shawn