IMac 5k Factory Reset

Question

I am considering performing a factory reset of my iMac 5k. I'm not liking the way I setup the user accounts and share settings (it's a home computer shared among family members). And I'm finding some issues with my iTunes music setup.  I set it up right after Christmas and still my original files on my pc so I won't be losing much by doing a reset.
My questions are:
What is the best way to do this (I've briefly viewed a coupke of videos)? Any recommended articles?
Will the steps for factory reset make computer like it was "out of the box"? Including all user accounts fully deleted?
is there any risks involved or is a reset I'll-advise?
I am new to iMacs and seem to much more now than I did 2 weeks ago. But still have a lot to learn.
Thanks in advance advance for any assistance with my issue.
Jeff

Answer 1

Install or Reinstall OS X from Scratch
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
Boot to the Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Erase the hard drive:
  1. Select Disk Utility from the main menu and click on the Continue button.
  2. After DU loads select your startup volume (usually Macintosh HD) from the
      left side list. Click on the Erase tab in the DU main window.
  3. Set the format type to Mac OS Extended (Journaled.) Click on
      the Erase button and wait until the process has completed.
  4. Quit DU and return to the main menu.
Reinstall OS X: Select Reinstall OS X and click on the Install button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible
           because it is three times faster than wireless.