First question is WHY do you want to ground it at all?
RF ground? Safety Ground? Lightning Ground???
For any balanced type antennas, An RF ground is not really needed.
If your house has the 3rd prong grounded outlets, That is all the safety ground you need.
(Most of the little blurbs you see about "grounding" are still holdovers from the 1940's or 50's before the widespread use of grounded power outlets.)
AND a lot has been learned about proper protection from lightning since then........
For a good lightning ground, It is a huge discussion and fairly complex to properly protect a station.
About the easiest way to start is to drive some ground rods outdoors, Twice the distance apart as the depth, Use heavy copper wire to join them, Run flat copper strap to the house where the coax enters and mount coax switches on that flat copper. Just switch the coax to ground when the antennas are not in use.
Be sure to bond the antenna or tower mast to your ground system, And also bond all grounds together. (Power, telco, Catv, etc.)
Note that I said that is just a start.......
The best way to protect equipment if you do not have a really good system is to also completly disconnect the radio during a storm. But be SURE that you have the coax grounded, As with the before mentioned coax switch to put the antennas to ground!
Simply "disconnecting" any coax and just leaving it lay, Or putting it in a glass jar as some do is pretty foolhardy and dangerous!
For some good info on lightning protection see this site: http://members.cox.net/pc-usa/station/ground0.htm