Here is my newest tutorial. It doesnt even seem fair to call it that, it took me two seconds to do this.
To correct white balance in Photoshop on a JPG image simply follow these two steps. Doing this can possibly save you lots and lots of time editing.
Open the curves layer mask. Select the gray eye dropper (circled) and then click on the white of the eye. Click around the white until you have the WB you want and say OK.
Now the top photo is much closer to the bottom photo by comparison. It only took two seconds!