Oh, you DEFINITELY should do it! It's the best thing I've ever done. It's not always easy, but it's SO rewarding to know you can make a difference in an animal's life. My advice? You're going to see some hard things, and while it's important to have a thick skin and be able to compartmentalize, you should never lose your empathy. One of my classmates said it best - "Never toughen up. Animals deserve our tears."
Feel free to ask me anything if there's something specific you're interested in!