Just make sure you boil it!! Use a pot big enough to fit the entire piece or wood in and boil it for a couple hours. If you dont have a pot big enough, go out a buy a Lobster Pot. They're cheep and big. The water will turn brownish in color (from the tanis in the wood), and really start to stink so make sure you have some decent ventilation. Dump the dirty water and boil it again. This will also help to waterlog the wood so that it will properly sit on the bottom of your tank w/out weighting it down.
I've got three pieces of wood in my two tanks that I put through this process and haven't had any problems with it (yet).
I much prefer going out and finding my own wood, especially if you have something particular in mind (I'm current searching for a long branching piece to use in a Paludarium). Most online stores which I have found do not allow you to choose from pictures of actual pieces of driftwood, only categories like size, style.