Make sure that you buy a "chrome" wheel cleaner as using the wrong wheel cleaner can make things worse. Soak the wheels with the cleaner as the label tells you and don't let it dry. Hit it with a "wheel/rim" brush, something that won't scratch the wheel but will take off the dust. You might have to repeat that step depending on how bad the dust is caked on. There's also chrome polish for wheels that will help protect the wheels and make it easier for the brake dust to come off.
The biggest thing I think is to clean your wheels frequently so that the brake dust doesn't burn into the wheel when it gets hot.
Take a look at autogeeks.net, they have a lot of videos on how to take care you truck. They sell a lot of stuff too but it's a little too expensive for my taste.