Testing procedures for new network implementation?

Hi All We are in the process of planning for the upgrade of a 3Com network. The new infrastructure will be comprised of 3Com 4950s with XRN and a dozen stacks of 4400s. What are the best practices of testing the new implementation? Any advices or suggestions would be greatly appreciated. The only software that we have is the 3Com Network Director. Thank you in advance. Wayne Chow Network Administrator Faculty of Dentistry, University of Toronto