If you havent synced to a computer before then see if this page helps : https://discussions.apple.com/docs/DOC-3141
In terms of updating the iPad, your games progress should be included in the backup. How long it takes to udpate will depend upon your content on the iPad (it will backup and restore it, though the contents of the iPod and Videos apps aren't included in a backup) and wifi speed - the iOS update file is something like 700 meg so may take a while to download.
To update, connect the iPad to your computer's iTunes and copy any purchases off the iPad to your computer via File > Transfer Purchases (File > Devices > Transfer Purchases on iTunes 11). You may also want to copy photosand any important documents off the iPad as well e.g. via the file sharingsection at the bottom of the device's apps tab when connected to iTunes, via wifi, email, dropbox etc - they should be included in the backup, but it's best to havea copy of them outside of the backup just in case. You can then force a backup of the iPad by right-clicking the iPad 'Device' on the left-hand side of iTunes and selecting 'Backup'.
Then start the update by selecting the iPad on the left-hand side of iTunes (on iTunes 11 you can enable the left-hand sidebar via option-command-S on a Mac, control-S on a PC), and on the Summary tab on the right-hand side clicking the Check For Updates button
Updating to iOS 5+ : http://support.apple.com/kb/HT4972
An iPad 1 will update to iOS 5.1.1, and an iPad 2 and 3 to iOS 6.0.1 (which is the only version that is 'signed' by Apple), so you will lose the built-in YouTubeapp and the Maps app will change.
