IIRC, the "right" and "left" labels came from seating. In a hall (I can't remember if it was one of our congressional halls or the British Parliament or where), it came to be that the liberals would tend to bunch up together on the left side of the hall, while conservatives tended to bunch up together on the right side of the hall.

I don't know where the label "conservative" came from, but I believe that "liberal" was originally used to describe people in Europe during the Renaissance who were anti-monarchy yet not radical enough to be democratic. Ironically, their views are more appropiately compared to modern-day conservatives... *shrug* Liberals were the moderate-right of the day, with monarchists being the extreme-right, the democrats being the moderate left (extreme left, with liberals being in the middle, before Marx), and after Marx, the communists became the extreme left.