You're going to put them into three categories: 1) Items to keep 2) Items to throw away and 3) Items to give away. Once you've sorted all of your belongings, throw away your second pile. If it's in disrepair or you never use it, chances are no one else will use it either. Let the items you need stay put, and make a plan for your giveaway items. You can give them to charity and receive a green tax credit, or you can hold a yard sale or sell the items online.

Angie's How To Clean Your Garage
It's normal for a garage to turn into a glorified storage closet, holding everything from Christmas decorations to child's toys. Designate time to clean your garage so you know what to keep, what to throw away and what needs a good dusting. With a clean garage, you can utilize the space to its fullest potential.
3 pros!
Go through everything and sort it into piles. For example, have a pile for tools, a pile for ornaments and a pile for old sports equipment.
For example, if most of the items in your garage are sports related, then you should opt for metal shelving and hanging hooks rather than large boxes. Also, think vertical. Is your garage high enough to add a shelf above your cars? If so, what would you store on that shelf? Remember, you're trying to utilize your space.
We recommend investing in clear storage bins, because you'll be able to easily see what's inside the bin. If you decide to opt for dark bins, be sure to label them correctly. Organize each pile into its own bin.
Always store substances like paint, pesticides and auto fluids in their original containers. If they're not in their original containers or if the containers are damaged at all, get rid of them. If you have pets or children, make sure that your containers are high and out of reach. Warning: as little as one tablespoon of antifreeze can kill a dog.
Propane is highly combustible! Anything with propane should be stored at least ten feet away from the house.
If you're storing a ladder, store it horizontally at floor level.
Check to make sure it's still in working condition. It's important to have a fire extinguisher in your garage!
You want to make sure that there is ample space for your car. Using chalk, draw a line from the garage door opening to where your car would be parked. Make sure none of the items you're storing in the garage pass that line.
Sweep the garage and dust any items that were too heavy to move.