I finally got my son (5) a little system from IKEA.
http://www.ikea.com/us/en/catalog/products/S19861419
This small system works well for us, but they come bigger as well. He has those red buckets on each side with a smaller green bucket above each and a really big blue one in the middle (like the size of a kitchen garbage can). They come in lots of sizes and configurations though. The buckets slide in on the rails, so each on has a place... we have his toys separated by time: vehicals, electronics, Legos, Barbies, tools, etc.
My son, is old enough not to need it, but our neighbors have labels with pictures on the outside of each bin.
He just gets out a bucket (or two) plays with it, and puts it back.
He also has a bookshelf for books and board games, and a chest for dress up clothes. The other random, large toys sit on top of the toy storage and a large canvas bin.
HTH
T.