How can I buy the right TV?

I really have no idea about the new TV's out there now. I am looking to upgrade to HD, but there are so many options and I just do not know what is right. I am mostly a casual TV watcher, and enjoy watching sports, not movies. But with LCD, LED, Plasma, etc...I have no clue what I am looking at and what would be best. I would like to spend $250-$350, if possible. Any recommendations?