Here's what Wikipedia has to say about it:
http://en.wikipedia.org/wiki/Far-right_politics
My own view is that the term 'far right' is almost inevitably linked to chauvinism and xenophobia (at the very least) and more commonly to racism.
That's unfortunate for those of us whose politics are well to the right (Margaret Thatcher was nowhere near enough to the right for me) but who are also Europhiles and who believe that immigration is beneficial. (i.e. because I'm to the right of Maggie, I'd like to use the term 'far right' to describe my political views but I clearly can't because I'm neither racist nor xenophobic!)