One of my favourite sites to visit on a regular basis is Kens Quiz Site. I have been using this site for at least 2 years or so now making sure to check back every time it is updated. There is already a wealth of good questions on there to get stuck into so great for revision, passing the time, or brushing up on weaker subjects. It jas helped a lot, particularity in pub quizzes and bringing me up to speed with all the "chestnuts".
Take a look yourself by clicking HERE