Start off with whatever image it is that you want to bevel. I used a clip art wood texture for this, but it can be anything.
Now, set up an alpha channel in the Channels palette. Name it whatever you want. Take the Gradient Tool, go into Options, and set it to foreground to transparent, with white as the foreground. Now, create gradients around the edgegs of whatever it is that you want to bevel; for this example I made a square bevel, but if you want you can bevel to any shape. All it takes is a bunch of gradients.
Now, go back to the RGB channel. Render Lighting Effects using the alpha channel as the texture channel. For this bevel, I used two directional lights facing in opposite directions, but it'll actually work just as well with an Omni or a Spot.
Voila! You have just created a Nice Bevel. From here, try to work out the Cool Bevel technique. Enjoy!