I'm putting together a photobook for my wedding which includes roughly 100 pictures in InDesign CS6. Each page will contain about 2-4 photos in a sort of collage style format. Wanting a get a good idea of the layout would look like, I placed all the images on the pages and quickly resized them via InDesign (mostly shrinking). The question is now.. should I go back and properly resize them in Photoshop and update all the links to the images? OR am I ok resizing them via InDesign?
Don't re-size in Photoshop. If you make the photos smaller you're destroying information. You're okay re-sizing them in InDesign. You might want to consider using Adobe Photoshop Lightroom to do this sort of thing in the future. As the name suggest it works really well with Photoshop.