How do you find duplicates in the same album? I keep creating albums and it's frustrating because I keep having to go back and personally scan for any duplicates. Isn't there a shortcut to finding these?

I'm knew to the iMac, although I've been using my Macbook Pro 2011 for some time and I love it. I've had an iPad and used the iPhone 5 and love the streamlined way you can share pics etc. between all devices. However, I've never used the iPhoto program until now. I am trying to organize my photos into albums and it is frustrating because I select photos from the main "Photos" on the Left Sidebar and because I have so many photos I tend to put duplicates into my albums. Then I have to spend hours searching to make sure there are no duplicates before I upload them to my website. This is tedious and time consuming. Surely there is an easier way to find all the duplicates IN THE ALBUMS I CREATE. I've looked everywhere and I can't find a sorting tool to put all the duplicates side by side so I can delete the proper ones.