You will also be required to register with Microsoft. Yes it's a pain but given what you're getting not that bad. If you have a Hotmail or Windows Live account already then use that. If not then you will need to sign up (it is free) for one.You'll need a reasonably fast Internet connection to the PC where you are going to install Visual C# 2008 Express Edition. Dial-up will not cut the mustard for such a big download! If you have installed any other Visual Express Edition (C++, Visual Basic) and have already downloaded the MSDN help then the download will be approximately 30MB.
The download page is on Microsoft's website for all their Express products. Microsoft Express Products.
On the next page : Download and Install Visual C# 2008 Express