I think that SBB has the largest collection of freebies available though to access them all you need to subscribe to the site. Another way to find freebies is to click on the digital freebies counter at the bottom of this web page. That will take you to a ranked list of sites that offer freebies.
Since you're using PS7 you might also find useful brushes or custom shapes that you could use similarly to diecuts at
Adobe's Studio Exchange.
HTH!