ipad charging problem
This page from Apple details how to charge an iPad.  It recommends plugging it into either the 10w Power Adaptor that comes with the iPad or a high powered USB 2 port.  Some USB2 ports are not high powered and will either not charge the ipad or only trickly charge it very slowly.

This article details how long it should take to charge the iPad with various techniques.  As you can see charging the iPad with the charger it comes with takes about 3 hours (to 80% capacity).

If you are not getting satisfactory charge times (and are using the recommended chargers), then you should book to have your iPad checked out at an authorized Apple repair centre or Apple Store.