This is straight forward:
1) Mysql database holds 3 piece of information-
2)Text to put centered under the image (allow for Link tag)
3)Link for image
2) Have PHP pull randomly one of the rows of data to display each time the page is loaded
3) Have a border around the image and text. Allow for the text to have a background color. Simply stated--A table with two rows 1 column center. See attached jpg.
That Does it.