Part 1: Getting your Google calendars to iCal.
1. Starting with Google Calendar on the web, Click settings,
2. Click the calendars tab,
3. Double check the sharing
Depending on which calendar you are trying to subscribe to, you may have to click on the “Share This Calendar” link, to the right of the calendar name, and adjust the sharing settings for the calendar.
4. Click the calendar name.
5. Click the ICAL icon,
Note that there are two ICAL icons on the page. Use the bottom one, the “Private Address” one.
6. <Command>-click the URL to get the popup menu of options.
Click “Copy Link”.
7. Then, in iCal, Use the “Subscribe…” menu item,
8. Paste that link in to it. Click OK,
9. Choose how often you want your Mac to request your calendar from Google.
10. And you are done with part 1: you've got your Google calendar showing up in iCal.
Part 2: The rest of the How To is on Apple’s website: How to Sync iCal with iTunes. Once you have your events in iTunes, then iTunes will sync them to your iPod.