[onewhippedpuppy]

It's a garage, not a storage shed. Therefore, anything not used in the garage should go away. That means couches, clothes, etc. Throw it away, have a garage sale, rent a storage unit, but make it go away. Then build as many shelves as you can fit, high enough that you can still hang stuff under them. Put the bigger stuff on the shelves, narrow long items (rakes, cords, etc) hanging on the wall. For lots of little stuff like oil bottles or cleaning supplies, buy a shelving kit at Home Depot or Wal Mart that you can push against a wall. For any really big stuff like ladders and bikes, hang them from the ceiling. Don't miss areas such as above the garage door for shelves, it's a great place for stuff you never use.

Yep, I'm pretty OCD. Get rid of a bunch of the junk, then get to work. In a nutshell, get everything off of the floor and onto shelves, really that's the key.