For a rectangle shape, the coordinates are entered like this: x1,y1,x2,y2
x1 and y1 = top left corner
x2 and y2 = bottom right corner
So just open up the image in PSP or PhotoShop or any good graphics program, find the rectangle you want to add a link to, and hover over each of those 2 corners. In the status bar of the program, you should see a pair of numbers that change when you move your mouse. Those are the x,y coordinates of the pixel that your cursor is currently on.
If the top left corner is at 20,35 and the bottom right corner is at 100,60 then the HTML would be like...
<area href="http://example.com/" shape="rect" coords="20,35,100,60">
Of course, there are better and more precise ways to find coordinates, but I'm too lazy to write more.
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