WordPress.org

1. Download the zip archive/plugin.
2. Extract the zip archive/plugin and move the directory/folder "sodahead-polls" (containing "sodahead.php" and directory/folder "sodahead") into your wordpress wp-content/plugins/ directory/folder.
3. Open the wordpress admin interface and click the "Plugins" heading.
4. Find the "SodaHead Polls" plugin in the listing, and click the "Activate" link.

Widget:

1. Click the Widgets option under the Appearance menu.
2. Drag SodaHead Polls to the Sidebar.