Printers ready? Here's a super resource for freezer cooking: printable labels for frozen foods. They've got that Martha style, but come with a super innovation: an embedded calendar to make it easy to mark the "frozen on" date.
Martha advises using a full-page label paper to create stick-on labels, but it's simpler and cheaper to print on inkjet paper and slide the label between double freezer bags.
The printable is in .pdf format, so you'll need the free Adobe Reader to print:
Attacking clutter, the hard part is making the decision to part with an item! Don't undercut your efforts with second-guessing. Use black plastic garbage bags or lidded boxes to hold de-cluttered items for sale or donation ... and once the item's in the bag? No peeking!