Some things to try on yur Mac.
Restart your Mac and depress the Shift key during startup. This will boot the Mac into Safe mode, which "fixes" some problems. Then restart normal.
Have you repaired Permissions?
Uninstall iTunes and then reinstall.
How To Completely Uninstall and Remove All Traces of iTunes
http://zardozz.com/zz/2008/04/how-to-completely-uninstall-and-remove-all-traces- of-itunes.html/
iPad not appearing in iTunes
http://www.apple.com/support/ipad/assistant/itunes/
iOS: Device not recognized in iTunes for Mac OS X
http://support.apple.com/kb/TS1591
iOS: Device not recognized in iTunes for Windows
http://support.apple.com/kb/TS1538
iTunes for Windows: iTunes can't contact the iPhone, iPad, or iPod software update server
http://support.apple.com/kb/ts1814
iTunes for Windows: Device Sync Tests
http://support.apple.com/kb/HT4235
IOS: Syncing with iTunes
http://support.apple.com/kb/HT1386
Apple - Support - iPad - Syncing
http://www.apple.com/support/ipad/syncing/
iTunes 10.5 and later: Troubleshooting iTunes Wi-Fi Syncing
http://support.apple.com/kb/ts4062
iOS: "Not enough free space" alert when trying to sync
http://support.apple.com/kb/ts1503
On your iPad, Try this - Reset the iPad by holding down on the Sleep and Home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons. (This is equivalent to rebooting your computer.) No data/files will be erased. http://support.apple.com/kb/ht1430
Cheers, Tom 😉