They do kill a lot of people off, but it isn’t as many main characters as most people like to boast about (including me at times :3 ). If you enjoy sword and sorcery, fantasy, and political intrigue, than Game Of Thrones is for you. The first few episodes are fairly slow, but it picks up over time, and by season 2 (there are only 10 episodes per season), the plot is in full swing and things start happening a mile a minute.
So I say give it a try, but give it time to get things going.