You need Android 4.1 or higher for Google Now (not Google Search).
There is the Google search widget and there's the search dialog.. Search Overview
The Google Search widget can be used by holding down a blank part of the screen.
A pop up on the screen should say Widgets. Click on Widgets then scroll left or right until you find Google Search.
Hold down on Google Search and drag it to the desktop where you want it to live. Now you can easily access Google Search on your device.
How to use Google's "Ok Google voice search actions" Ok Google voice search actions
If you aren't getting notifications for your Now cards, follow the instructions in the Youtube video to fix the issue:
How to enable Google Now..
(you may have to copy this link into your internet browser)
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