SQL Server 2008 Editions

This is where you can get SQL Server 2008 Management Studio Express (free SQL client)
http://www.microsoft.com/download/en/details.aspx?id=7593

This is where you can get SQL Server 2008 Express (free SQL host)
http://www.microsoft.com/sqlserver/en/us/editions/express.aspx

And this is where you can find more about the other editions
http://www.microsoft.com/sqlserver/en/us/product-info/compare.aspx

I just noticed today that some people actually write (not just say) SQL as Sequel. :)
Found a discussion about it here as well.
http://discuss.fogcreek.com/joelonsoftware/default.asp?cmd=show&ixPost=62158