Why is my Jamis Road Bike skipping

I assume you're talking about the drivetrain skipping.

If the chain is jumping past certain cogs in the cassette (or sprockets in the freewheel) this could be an indication that your derailleur hanger is out of alignment. Park makes a special tool for this, though it is generally too expensive to buy for casual use. This adjustment is easily made by shops, and generally inexpensive to perform.

If the chain is slipping while in a certain gear, it is likely due to a worn chain, sprocket or chainring -- though occasionally proper lubrication of the chain will fix it.