I guess there are 2 real questions here.
1. Should I resize the images in PS before printing
2. Is there any software (or a way with CS3) to print standard size photos with the option to have multiple different photos on a page (like with the Microsoft print utility)
1. If you do your own printing, crop (if necessary) and resize first. If you send them out to a lab, there is no need to resize, just make sure the aspect ratio is correct for the print size(s) you want. The lab printer's RIP software should handle resizing for you. If not, use a better lab.
2. IIRC yes, and I think it's not actually in CS3, but in Bridge.