Rehoning basically means "wet sanding" the floor to remove scratches, dull surface, etc. After it is rehoned a special powder is used to bring the floor up to a polish.
Grinding the floor is the same thing, only more aggressive. Any lippage in the marble tiles are ground down flush and the completed floor is like a sheet of glass. If you can't slide a dime across the floor without it catching on an edge of marble tile then you know it's not ground down.
Crystallization is a chemical process used to burn a polish on a marble floor.
None of these options are a do-it-yourself job.
NOTE: I have seen tile installers lay marble like it were ceramic tile and grout the floor with a sanded grout. If your floor was installed this way none of these options I have listed will work to your satisfaction. The sand will break free and scratch the floor.
More info on stone care: http://www.ntc-stone.com/tips.htm#tips
HMK carries a marble wax: http://www.hmkstonecare.com/products/s34.htm
Understand that floor waxes are a high maintenance option.