There is only one way to know that the real estate market has bottomed out and that is when the real estate prices start going up.

there is no guarantee that prices have hit bottom yet- but that doesn't mean that you can't get a great deal now. There's no telling how long the housing crisis will lag on. Here's what you need to know before you start shopping.

Gary Keller, the author of "The Shift" explains it as the real estate buyers being in the lucky or unlucky zones or purchasing a home in the "safe" zone.

Gary says "You know the market has bottomed out when it starts back up and you know the market has peaked when it starts back down. The safe zone is where smart people plan to buy and sell. Anyone who buys at the top of a real estate market is just unlucky and anyone who buys at the bottom of a market is just lucky."

Gary goes on to say that "people who buy in a buyers' market are the smart ones.  They're buying in the safe zone and living in the area of certainty. They're not unrealistic and they're not greedy. They know they can't predict the end of a bust, but they can see when a market has fallen considerably."

Rule #1 You can't time the bottom

You may think about trying to time the bottom. Resist. It's harder than you think and the best buyers have had in two decades with inventories up and mortgage rates low.

Rule #2 One reason to buy now-mortgage rates

Homes are plentiful and will remain so, but financing will be getting more expensive. There could be a penalty for waiting to buy even if prices fall.