Method A

1. Open the image and make to the size required, which is:

     Horizontal (landscape) image: 22cm x 15cm
     Vertical (portrait) image: 17cm x 11.5cm

2. Make certain the the Background colour is set to white, next, go to Image > Canvass Size
    Make the width 28cm and Height 20cm. Click OK
    The image will now be in the centre of an A4 page

3. Add text, title and your name - for the sake of conformity and clarity use Ariel as the font (size 14 point for the image if the resolution      is 200ppi)

Method B

1. File > New

2. Set the size to:
     Width: 28cm
     Height 20cm
     Resolution: 200ppi (or whatever your standard ppi usually is - or set it to be the same as the image you are to import if you already      have the image prepared at the correct size - as below in step 3)
     Contents: 'White'
     Click OK

3. For the image you wish to 'import' to the newly created A4 page make the 200ppi at the correct size for the page.
     The recommended sizes are:

     Horizontal (landscape) image: 22cm x 15cm
     Vertical (portrait) image: 17cm x 11.5cm

     Should the image be the wrong size then use Edit > Transform > Scale to adjust the dimensions. Don't forget to hold the Shift key      down to maintain image proportions.

4. Copy & paste the image to the newly created blank A4 sheet and centre the picture

5. Add text, title and your name. And for the sake of conformity and clarity use Ariel as the font, size 14 point for the image      size/resolution above