This Omega 3.x Doc page is under construction!
The Non-Drush Method
After you have downloaded the Omega theme, unzip it and place it's content in /sites/all/themes or /sites/example.com/themes. Open the Omega folder, inside you will find a folder labeled "starterkits", which contains the starterkits available for use as a base theme. You will use one of these to create your custom theme in the next step. Choose either HTML5 or XHTML starter-kit and copy this folder back to your sites/all/themes folder . If you have a particular requirement for XHTML then choose the XHTML. Otherwise, HTML5 will be the better choice in terms of long-term compatibility with the modern web's changing Browser standards.
This will be your new custom theme.
The first thing you need to do is rename the starterkit folder to your new custom theme name. Don’t use any spaces or dashes (-) in your name, or it won’t be recognized. Now open this folder and locate the starterkit.info file. Rename this file to the exact name that you used for your subtheme folder. It is imperative that the name of your theme folder and your .info file match, otherwise your theme will not display. Your theme folder should resemble the following example:
sites/all/themes/mythemename & sites/all/themes/mythemename/mythemename.info
After you have created your folder, and renamed your .info file, there is just one more step to complete before you load your theme, you need to edit your .info file to reflect your custom theme name and settings.
Open yourcustomtheme.info in a text-editor and look for the following lines:
name = Replace the text here with yourcustomtheme name
description = Replace with a description if you'd like (make sure to give the Omega team a shoutout)
VERY IMPORTANT
hidden = TRUE REMOVE THIS! Without removing this line you will not be able to find your theme in the admin menu.
starterkit = TRUE Remove this as well since you are no longer creating a starterkit.
For now that is all you need to edit. Save yourcustomtheme.info and head over to admin/appearance. There you will find your newly created subtheme all ready for you to enable and begin using.
The Drush Method
coming up soon!