Grant Fritchey gives an introduction to wait stats:
Now, you have a meaningful list of wait statistics that will tell you exactly why, if not where, your server is running slow. Unfortunately, these waits still need to be interpreted. If you read further on Paul’s blog, you’ll see he has a number of waits and their causes documented. That’s your best bet to start understanding what’s happening on your system (although, I hear, Paul might be creating a more complete database of wait stats. I’ll update this blog post should that become available).
Wait stats are fantastic tools for figuring out your server resource limitations given the server’s historic query workload. They’re the first place to look when experiencing server pains.