Link to good advice on roofs

Have a look at "Martin's Ten Rules of Roof Design", over at Green Building Advisor.com, for some solid, practical advice on how creating durable, functional shelter.  I especially like numbers 2, 4, 7, and 9, and the section titled "A preemptive comment directed at indignant designers". 

A roof is, after all, the most essential component of a house.  Why risk compromising it?

I'll add one point to those in the link above.  The roof on this pictured building is superior to most of the roofs in your neighborhood in at least one way: nobody is under the impression that this roof is forever.  Anyone can see that it will need regular maintenance.  Unfortunately, too many people I know get a roof, they think it's a done deal, and they never think about it again.  Until it fails, sometimes catastrophically, thanks to lack of maintenance.