There are a number of auto degreasers that are available for this purpose as well. Consult the shop you are buying your paint from - it is likely they carry a good cleanser. Don't leave a single fingerprint on the truck - the finger oils may cause trouble.
Then, take a tack cloth (or several) and wipe every inch to remove the dust within the last 5 minutes or so before you get to shooting the paint (this is a good job for 10-12 year old helpers).
Don't forget to get your shop super clean and as dust free as possible before you get rolling to minimize imperfections in the paint. Good luck and let us know how it goes.
