Find out angle with measure tool > create a crop at 6x4" or whatever your print size is going to be > rotate crop to desired angle > crop with a straightened image that is 6x4".
In the crop options area, there is a text field for resolution, I just left it blank like Mike did in the movie. Whenever I go and save my photos again as a .jpg the resolution goes from being 72 DPI to 359 DPI, which I though was an odd number.
Do I not need to worry about this? Or do I set the resolution to 300 DPI when I crop the image?