Sorry, but while we still do support .NET 3.5, we dropped support for VS 2008 a long time ago.
You will need VS 2010, possibly/probably you qualify to get VS 2010 free via the Microsoft Website Spark program.
At some point we will also drop support of .NET 3.5, so we recommend everyone to move to .NET 4 as soon as possible and I would not recommend setting up new sites with .NET 3.5. .NET 4 has been out for more than a year and has many benefits compared to .NET 3.5.
See also The .NET 4 Transition Plan