. . . and you will do it a few times over if you want to give your mss a thorough check. 
Usually after what you think is your final draft and then maybe just some individual pages . . . if you haven't wrecked your page numbering system when you print off the final, final draft.

Ah i haven't numbered anything yet. I have a rough format i.e borders, double spaced, font 12 etc but I am leaving the typesetting and final formatting to after the editor goes through it.
Here is my current process:
Right now I have it in PDF format, reading through, correcting errors as I go in the word doc and marking down on a seperate paper areas that need to either be improved or removed or moved around. ( long old process... urgghhhhhh!! )
Next step will be to do those improvements
Then i will read through again, this time marking the areas where the chapters will be ( right now I just have it in scenes ) I will create the chapter areas.
After that I will go back through again to see if there are any more improvements I can make
Then I will hand it over to 3 people to proofread ( each will take 100 pages ) after they are done
I will then hire an editor to go through it
Once back I will go through it one final time.
Then I will have someone get it ready for amazon and smashwords