As usual there are a number of prior threads on this subject. Here's one: lightning
. My post in that thread has this link http://www.kastenmarine.com/Lightning.htm
which is required reading on this subject.
As I recall all the material, you want to have your mast gounded, and that will provide primary protection to the people on the boat and to the intergrity of the hull, in the case of a lightning strike. If your boat doesn't have one, which I would find surprising even on a low budget production builder, then you should install such as described in SD's first post above.
I make a distinction between grounding the mast and a full protection system that bonds all metal parts to ground. The first is essential and should be universally provided, the second is less common and expensive, and in my personal opinion, the retrofit cost not worth the benefit.