The following management summary overview video covers many aspects of Public Key Infrastructure [PKI] and Certificate Authority [CA] systems. Specifically this video looks at Digi-CA™ [1], explains how the software was designed and the many different ways it can be delivered.
Links:
[1] http://www2.digi-sign.com/digi-ca
[2] http://www.youtube.com/watch?v=JveIu7_r7ao
[3] http://www2.digi-sign.com/product/digi-ca