To eventually looking like this
Better, but the drwers are still sagging in the middle
To finally this edition .... straightened right up.
Here's how it goes in basic photoshop, including the relatively inexpensive version, Elements.
Edit .. Transform .. Distort ... Little boxes/handles appear at the corners of your photo
Drag the boxes around until you get it the way you want it and hit enter. You may have to crop and fill various parts of the results after you do this, but eventually you'll be able to use this feature in almost no time, and you'll never email a crooked picture again. "Practice makes perfect. " I'm sure other photo editing programs have this feature though I have not had experience with them .....I'll cover the cutting out of photos and the 'Warp' feature (to correct spherical distortion) found in more advanced versions of Photoshop later .... Click the photos to enlarge .... leave a comment if you want ....