The iPad 2 came out in March 2011 (and can be updated to iOS 6.0.1), if it's older than that then it must be an iPad 1, so the highest iOS version that you can install is 5.1.1 (the first gen doesn't support iOS 6). If I'm looking at the correct apps then the ITV Player app appears to only require iOS 4.3+, as does TVCatchup.
If you aren't iOS 5.1.1 (Settings > General > About > Version) and you want to update (if it is an iPad 2 then it will update to iOS 6.0.1), then connect the iPad to your computer's iTunes and copy any purchases off the iPad to your computer via File > Transfer Purchases. You may also want to copy photos and any important documents off the iPad as well e.g. via the file sharing section 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 have a 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, 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
In terms of the new iTunes, you can enable the left-hand sidebar via option-command-S on a Mac, control-S on a PC