Right now, there are 3 types of transactions (normal, short sale and foreclosure).
It's good that you asked about this, because now you'll know which kind to go through...
Short sales - when your contract with the seller is subject to the short sales bank approval (and seller having a true hardship). These could last from a few weeks to 3 years...because some banks and their underlying investors are just terrible/could care less about homeowners/buyers.
While you are waiting, other good deals could come by - but you'll be in contract already...
You got to really love your short sale house to stick around for however long it takes.
If you loose patience, after the agreed upon "approval" time - like 90 -120 days (or more), you can exit the transaction (this has to be done right to protect your easy exit).
Foreclosures - bank owned sales - your agent will need to make sure to have a good attorney/title company check on liens and title issues that foreclosures often come with. These types of transactions take from 3 weeks (if cash) to 45-60 days (if financing). Sometimes, foreclosures offer teaser pricing - and end up sold above the market value, due to bidding wars. Multiple offers are pretty common on these...
Normal sales - some homeowners are very motivated and might sell at prices lower than short sales or foreclosures. Not to be overlooked!
Hope this helps,
Beachfront Realty, Inc.