Click on Card Catalog at Ness City under Library Services on the right hand side of this page then login using your library card number and password.
Click on the little arrow beside your name in the upper right corner.
From here you can see what items you have checked out by clicking Items Out on the left of the screen.
All of the renewable items will have the words Renew Item to the right. You can click on that to renew individual items or you can click on Renew All to renew all items that are renewable.
A confirmation window will pop up telling you how many items were renewed.