Currently Being ModeratedFeb 24, 2013 12:22 PM (in response to All_Time_Low)
Welcome to Apple Support Communities
1. Control+Click on the folder you want to change, select Get Info
2. Find an image you want to replace the original folder icon with. Copy it (⌘+c).
3. Click on the small folder in the upper left of the Get Info window so that a blue outline appears.
4. Paste image (⌘+v).