Tap the Google Search Widget on the Home screen.
Google
Now opens automatically and you can use the on-screen keyboard to
search or tap the Microphone icon to say what you're looking
for.
Voice Search
Tap here to search by voice.
Search Box
Tap here to type your search request.
Google Now App
Tap here to open the Google Now app.
Enter the text you’re searching for in the search box.
As you type, search results from your phone, previous search terms, and web search suggestions appear. Tap an item to activate that search result.
Tap the Search button on the on-screen keyboard to
search for the text you entered in the search box.
The bottom of the search results screen includes a search category bar. You can scroll through them, then tap one to display your results using only that category.