Borders - How to fit an image into a specifid print size

If you have a specific print size you want to output, here's how to create the canvas and make your image fit into it.

Open an image and activate the rulers.  <View> <Rulers>  Now you know what the size of your image is.  For output, it's best to be at the default 300 ppi.

Create the end document.  In this case you go <File> <New> and make your document.  In this case it's 8" high x 10" wide @ 300 ppi.  It'll appear on your desktop in a separate window.

Go back to your original image and <Edit> <Select All> (shortcut is CRTL-A) (for the Mac it's <Apple-A>) 

Then <Edit> <Copy>

Select the New Document (the 8x10 one) and <Edit> <Paste>.  If you are working with the original file out of the camera, then it should be bigger than the 8x10 document.

How to make the image fit?  Go to <Image> <Transform> <Free Transform>.  There should be a square box on the corner.  Since the image is larger than the box and you can't see the other size of the transform boxes, you can either make the image smaller or....

Use <View> <Fit on Screen> (Apple-0 (zero)) and all the boxes will be in view.

Click on the box in the lower right corner, HOLD THE SHIFT KEY DOWN, and click and drag the box until the image size is reduced to the size that you want in the box.  If you do NOT hold the shift key down, the image will get distorted.  Holding the Shift Key down, will maintain the aspect ratio.

Once it's size to your satisfaction, click in the photo someplace and move the image to where you want it placed in the box.. 

Once you're happy with the placement, you can either double click in the box OR hit the enter key and then you can start applying the background color and whatever else you want to do.