While the mini catalog is in effect, the stamp sets in it will be featured in the Mini Catalog and Previews category of the SU Gallery. You'll need to be logged into your SCS account in order to view them.
After the mini catalog is retired, the stamp set categories will be moved to the appropriate alphabetical listing in the gallery.
Here's a direct link to the Itty Bitty Bits category:
Stampin Up! Gallery: Itty Bitty Bits by kgilmore - Page 1 - Cards & More - Splitcoaststampers