For a lot of people, the garage is like a big, cluttered closet -- you throw in all the unwanted stuff you can't find a home for, shut the door and hope it will magically disappear.
With your new, sun-induced lease on life, it's time to face the task and get it over with so that when you need that sprinkler in June, you won't be tripping on rakes and fumbling through bug-infested boxes.
Before you start organizing, you'll need to assign and arrange areas: Perhaps there's a hobby area in one corner and workshop equipment in another. Decide where these will go, then move on to figure out how to store everything.
After all, the biggest necessity for many families is storage space. Installing cabinets, shelves, racks and hooks may help immensely. Use boxes, baskets and old plastic storage containers from the kitchen to organize - adhesives in one box, paints on the shelves, etc.
And when you find that weird key that doesn't fit any of your locks, old electrical wires or things you think you want to keep ("just in case"), find a junk box for those too. And, of course, don't hesitate to toss anything you can.