Every day, entrepreneurs with new ideas are discovering that the domains they'd like to build business on have already been registered, most likely by a domain speculator.
Before you make [the mistake of choosing a misspelling or invented word] for your startup, get familiar with practices you may be able to use to acquire domains with terms acceptable to you. To get you the scoop on what's worked for the industry, we talked to a number of experienced domain buyers, sellers, and brokers about how they handled their deals.
Solid advice, worth a read to get a better understanding of how to approach domain brokerage as a buyer. Also worth reading alongside this: How to choose a domain name, Keep your domain name by registering it right away, and Tools to find available startup domain names.
Here's also an article on how to grab expiring domains, via Aditya Chadha, and a Fred Wilson article about finding and buying domain names.