1. Wash truck
2. Iron-X or Adam's Deep Wheel Cleaner sprayed on entire vehicle
3. Let sit about 5-10 minutes and let it dissolve the rust.
4. Very thorough rinse.
5. Clay Bar paint.
6. (Optional) Polish your paint. Not necessary to remove the rail dust, but since you already stripped the paint, now is the time to polish out the scratches.
7. (NOT OPTIONAL) Protect your paint. You just stripped everything off your truck's paint; now you need to protect it. You may use a sealant or a wax to coat your vehicle and add protection. Personally, I like that sealants past longer so I seal the entire truck with Adam's Quick Sealant. I'd like to try their new Liquid Paint Sealant now that it is available.
8. If you want to add wax for additional shine after sealant, go for it. If you're just waxing don't worry about it.