A lot of computers don't provide enough power to their USB ports to charge the iPad at a sufficient rate - it may still be charging slowly, and should be a bit quicker if the iPad's screen is off (if you leave it for a while and then disconnect it from your computer you may find that it's battery percentage has gone up). The wall charger is usually the most efficient way to charge the iPad.
Charging the iPad : http://support.apple.com/kb/HT4060
In terms of the photos, what happens when you try to sync them to the iPad from your computer's iTunes ? Have you tried deleting the photo cache from your computer and then re-trying the photo sync and see if they then copy over ? The location of the cache, and how to delete it, is on this page.
Syncing photos : http://support.apple.com/kb/HT4236
If the iPad isn't recognised by your computer's iTunes : http://support.apple.com/kb/TS1538