So do you know all your students' names yet? I sure don't but then again, I have about 2000 students in the whole school that are "mine." Even as a teacher I had trouble learning names fast enough. Of course you always have those who are answering every question already so you know them. But would you like to know a trick to ensure you pick different people to answer questions in a discussion?
Try this free site. The Randon Name Generator from Class Tools.net is a fun way to make sure everyone is included in the discussion. You have to load the names first and then the site spins like a Vegas slot machine randoming selecting names. It even has sound effects! You have the option to remove the name once you've called on a student or you can leave them in the rotation just to keep everyone on their toes!
You could use this to pick people to answer in discussions, pair up random names for partner activities, or other groupings. We've even used it in inservice trainings to make sure everyone is paying attention. It's so embarrassing to be called out in front of your peers and not know what's going on--whether you're a teacher or a student!