Component based design using .NET framework

i wondered if anyone could help or at least direct me in the direction of good sources where i can get this right.

Basically
Scenario:
A company needs to exploit recent advances in software technology.

. The system to be redesigned for the .NET framework
. The new system should provide facilities to interface with the systems of rental companies to allow real-time availability checks to be made
. The new system should be designed to be able to interoperate with other external systems when such opportunities arise

task:

ive got to create a component based diagram,
UML 2.0 component diagram
spec for each component
justifictaipon for major design decisons

if anyone would be willing to help/guide me, please let me know.

thanks
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