How to share stuff from Google Drive to Google+
1. Open Google Drive
2. Open the document you want to share
3. Copy the file's URL from your web browsers bar
4. Past the URL into the share box on Google+
5. Select the circle of the names of individual people you want to share with
6. Click the share button
7. You're done
If you have signed into Gmail or any other Google service. You can press the +Share button found on the top right-hand corner to share.
How to share from within a document, spreadsheet or presentation.
1. From within Google Drive open the document you want to share and click the share button on the top right-hand corner of your browser window.
2. You also need to make sure that the file is not marked private. It needs to be 'Public on the web' or 'Anyone with a link'.
3. Next to the share link via click on Google+.
4. You will now see the Google+ share box with the embedded document.
5. Select the circle or people you want to share with and click the share button
6. You're done
Learn more at the Google Drive help center