Or even who your MP is?
I'd be willing to bet that a great many people have no idea.
So it's a good thing that the nice people at the Guardian have created Ask Aristotle, a database that will tell you who your MP is and what they do in Parliament. The good thing about Aristotle is that all the information is linked from the one site, rather than having to go through the different layers of the parliament and House of Commons sites.
A site to have a look at is the Register of Members Interests. This list that tells who's got their fingers in the most pies. "Remunerated Directorship" is the term to look out for. It also shows patronage of charitable organisations and the like, so gives you an idea of what an MP believes in (or, for the cynics, believes will make them look good). Some of the Lords' lists are particularly interesting.
Go and have a look. Find out what they're up to and how they voted and what committees they're on. And find out their addresses and write to them about things that bother you -locally and nationally- it's their job to represent the views of their constituents.
While we're on the subject of government, if you ever want to know what county or district or borough a place is in have a look at Oultwood.com. They provide links to local government information worldwide.