Flanking

I was wondering if some of you warmongers out their could comment on Flanking. With no SoD in Civ 5, military strategies will be important. I'm be hearing alot about Flanking and the flanking bonus, but I am not sure how it would work, or how I should place my armies.

What I do know is that flanking means attacking from the side. But what should be your army composition to do so? How should you place your units, assuming one per tile. Also, how would you defended against it?

The flanking mechanic is more like prevention of flanking, as apposed to the true meaning of flanking.

Your unit gets +15% for each adjacent unit (up to 30%)

No. It is the number of units adjacent to the enemy unit, so there can be a bonus of +75%.