Oh my goodness, I am like a kid in the candy store with this one! I have been finding lost pieces and parts to so much of my digi-stash.
I've been ACDSee Photo Manager to organize my digiscrapping supplies & photos for about 5 months now. It's flexible for cataloging & powerful for searching.
A couple of great things about it are that you can search for whatever you've tagged and view white png files. I love how I can find just about anything I need with just one click!
And look, I can see my pngs!
You can find tons of helpful tutorials at digiscrapinfo.com, like Getting Started and Organizing your Alphabets. And a 30 day trial can be downloaded at the top of the tutorial page at that site.
DigiScrapInfo.com has a lot of helpful information related to digital scrapbooking. Nothing is being sold there. Just good advice when you get stumped while digiscrapping and organizing your stash.
You can pm me if you need more information.