I have a a twitter logo, jpeg, exported out of Photoshop...
I have it marked as a button, but how do I edit up, over, down, and disabled states so like when the mouse is hovered over the button, it changes color/appearance, kind of like around 3:00 here: http://www.youtube.com/watch?v=tNAde32pWT0
Thank you so much!
Here are some video tutorials that step you through editing the different states of a button:
This is part of a complete video series, which you can find here.
Creating buttons from Illustrator art (many of the basic principles of editing button states are the same regardless of whether your art is created originally in Photoshop or Illustrator).
This is also part of a series, which you can find here.
Hope this helps!