Depending on your circumstances, you can save a lot of money shopping early for things at online and in store sales. Many clothing stores have quarterly sales, where it's a good idea to pick up things for the upcoming seasons next year if you have growing kids. Other stores like Target, Wal-Mart and K-Mart have huge clearance sales on toys in July and January. Electronics and Appliances are discounted around each President's Day, and some places will even pay your sales tax.
Here are a couple of helpful links to help you plan when to buy things to save a little time and money. Do you have any other tips? If so, I'd love to hear them!
Consumer Reports Guide
My Tips for Saving Money All Year
Frugal Living Calendar