If you want to sync Google Calendar and Outlook, Google Calendar Sync tool is all you need. There are 2-way and 1-way┬ásynchronizing alternatives. Try it:
If you have Google Apps for Business (I mean you pay for the service), you can also use an excellent tool that name is Google Apps Sync for Outlook. It provides mail, calendar, contact, free/busy data syncronization capability.
Lastly, if you bored of Outlook (How can it be possible?) and want to move whole data to Google Apps, Migration Tool is for you: