We will be developing 3 asp.net web applications. Each of them will have it's own database. We don't want these applications to share resources because they're from different departments.
What is the recommended hardware setup that will allow us to have staging and production environments for each application?
I generally just have 6 boxes set up. 2 each for development, staging, and production...and then of course production can scale out from there. Then I use cruise control to push my code from one environment to the next. You don't need physically separate environments to run your 3 different applications.
Take a look at this for more information: http://stackoverflow.com/questions/1039741/svn-website-development-and-deployment-solution/1040056#1040056