You are looking on the right-hand side of iTunes when you've selected the iPad 'device' on the left-hand sidebar ?
If you are on iTunes 11 on your computer then you may want to re-enable the left-hand sidebar via control-S on a PC, which might make it easier to navigate and my instructions may make more sense.
To sync photos, connect and select your iPad on the left-hand side of your computer's iTunes (if you've enabled the sidebar), and on the right-hand side there should be a series of tabs, one of which should be Photos - if you select that tab you can then select which photo folders to sync to the iPad. There is a bit more info on this page. You will need to sync all the photos that you want on the iPad together in one go as only the most recent photo sync remains on the iPad - synced photos can't be deleted directly on the iPad, instead they are deleted by not including them in the next photo sync.
If you haven't enabled the sidebar, then from your library click 'iPad' at the top right of the screen and you should get a series of buttons along the top of the screen, including one for Photos