A strap style clamp like this,
http://www.solidsignal.com/pview.asp...ce=google_base or a bronze clamp like this,
http://www.alightingstore.com/1-25-i...ze-screws.html are good choices for making a reliable and lasting connection to a mast or tripod frame. It's very likely that the big box home centers will carry this type product in their electrical departments.
#10 AWG copper wire, insulated or bare is readily available at the same big box stores, in full rolls and by the foot. Solid or stranded is fine. Use this to run from the mast or tripod to the electrical service ground. The big box stores will have clamps like this,
http://www.homedepot.com/p/Blackburn...1-10/202907615 for connecting to a ground rod. Avoid sharp bends in the wire run. The mast ground can be any length... but try to use the most direct route if at all possible.
This graphic,
http://ecmweb.com/qampa/code-qa-95 is very generic, but it shows the common locations you might find the grounding cable that runs from your service panel to a rod driven into the ground, usually outside below the electrical meter. If you don't see a cable connecting to a ground rod, the National Electrical Code would direct you to several other places that are suitable sources of 'ground'. A clamp on the metal conduit entering or exiting the meter base is a viable option.
If you are not comfortable doing this work yourself, a licensed electrician should have little difficulty installing an Inter-system Bonding Termination devise for you. Example:
http://www.homedepot.com/p/Unbranded...IBTB/202194170 Then you would have a convenient and permanent connection point for grounding antennas, phone service and (yuck) cable TV service.
To complete the antenna system grounding, a coax grounding block should be installed close (10' or less) to the exiting ground rod or alternate connection to the electrical service grounding system. Use a short piece of #10 AWG wire to connect the grounding block to the electrical service ground rod. The coax from the antenna to the ground block should be run outside the building, then the 'output' of the grounding block can be run inside.
http://www.amazon.com/1GHz-Single-F-.../dp/B001I5610E
Here are a few illustrations that may be helpful.
http://ecmweb.com/code-basics/articl...sion-equipment While it's not just one or two sentences, it's fairly brief and has some decent graphics.
And lastly,
http://forum.tvfool.com/showthread.php?t=901 post # 20 is a summary