This is a very large topic (kind of like a PMO [smile]).
There are many ways to go about this -- from either the "waterfall" or "agile" slants.
Usually the main "real world" objective I find for building an Project Management Office (PMO) is to make people feel like they have "control" over their projects -- and this is usually their main downfalls.
The easiest strategy is to start identifying the projects in your portfolio -- this one step alone is usually worth the beginnings of an important conversation that follows... "What next?"
If you'd like to speak with me more about this, please let me know.
- michael vizdos