Hi Kelen, 
 
I just use google image search usually.  although here is a great resource that has royalty free everything from microsoft.  you just need to have a genuine copy of any microsoft product.
 
If you open your word or works program.
 
Insert clipart - so that the menu appears on the right hand side of the page.
 
There should be a link saying:Clipart on Office Online.
 
Click on that and it will take you straight to the right place.  I love this resource.
 
Also if you go into the search box within the clipart library you can ask it to search the online library :
Just click search all collections; web collections.
 
Good luck
Vicki