Hi ACiveE,
I am no expert but here's my personal experience: usually I inflate tires very close to the max. And, I tend to buy high pressure tires: Vredestein tricomp (clincher tires) and Vittoria Crono EVO (tubulars). My weight is under 130lbs and I've never had problems. A couple of my riding buddies are heavier (in the 190-230lbs range), and they also use mostly Vredestein tricomp or fortezza and inflate their tires close to the max.
Hope this helps