Have a look at this fun quiz from Google for webmasters. The questions are all objective multiple choices and are based on common queries in Google Webmaster Help Forum. I checked the questions & they have some pretty good questions about the problems that you face regularly as a webmaster like on multiple domains & ccTLDs, url changes or robots.txt etc. You can take the quiz till this January 27.
The answers are not available right away. Google will write a follow up blog post in their webmaster blog with the correct answers. Don’t forget to save your answers now before submitting. Then you can realize if you are making any common mistakes.