This series of blog posts is mainly focused on wheels but it has a lot of interesting tidbits on tires and tire pressure as well:

Road to Roubaix, Part 1 | SILCA

Road to Roubaix Part 2: Tires (and Pressures) Are EVERYTHING | SILCA

Road to Roubaix Part 3: We Just Invented the Future | SILCA

I currently run 23mm Continental Grand Prix on Flo 30 rims. Tires mic out at 26.5mm actual width and rims are 24mm wide. Bike + Rider weight is around 200-205; I've run between 55-110 PSI and have noted some significant differences in comfort but minimal differences in performance with respect to group riding and practice crits.

I tend to pinch flat if I hit any significant gravel or golden-bb type rocks under 70ish PSI and I get a harsh feeling ride that does not handle rough roads very well at anything over 100 PSI. With my combination of frame, weight and road condition I prefer 70-75 front and 85-90 rear. This gives me the best combination of comfort, handling and speed.