Of course the most important thing about both the old Gaelic harp tradition and its current revival are the people involved with it - without them there would be nothing else!
The old harpers are dead and gone, and most of them are forgotten. But I have started compiling a long list of old harpers. Some of the better known or more important harpers get their own pages: Carolan and Rory Dall; also Denis O'Hampsey, Rose Mooney and Patrick Byrne
I also started a list of old Gaelic harpmakers.
A good way to get involved is to join a society; the two main organisations dedicated to the Gaelic harp are the Wire Branch of the Clarsach Society, based in Scotland, and the Historical Harp Society of Ireland, based in Ireland.
On the internet there are three main discussion groups. Oldest, largest, and based in America, Wireharp covers modern folk harps with metal strings, as well as the old Gaelic traditions. Clairseach is smaller and more academic, focussing on the early Gaelic harp. It is owned by Alasdair Codona in Edinburgh. And in Ireland, Irishclairseach is used primarily to co-ordinate meet-ups and events in Ireland.