If you get the Normal Mapping shader working correctly then you're basically there. Normal Mapping is really just an impressive version of bump-mapping.

Typically, you use Normal Mapping to convincingly portray large bumps, like rivets and such. In those cases, your Normal Map will have some fairly high contrast around the rivet. To add small details like cracks or creases, you simply need to add or use some lower-contrast or finer-detail aspects to the image. For instance, if you convert a normal bump-map of cracks and grooves to a Normal Map, it will show small bumps and cracks. Also, when you generate a Normal Map from a high-res model, you can also usually blend the resulting Normal Map with a second bump-map to add fine details--at least that's true of ATI's utility.

Anyway, so if you just want to know how to convert a bump-map to a Normal map in Photoshop, there's a plug-in for it. I believe it's on the NVidia site, but it could have been ATI that I got it from. Check out the "Killer Normal Mapping Link" listed in the very first post of this thread for the specifics.