best place to get driftwood

You can get some down by the river, but be sure you boil it and soak it good before you put it in your tank. It won't be as clean as that you find in the LFS. It could contain disease and will probably release quite a bit of tannin that will make your water look a lot like a really big glass of tea. So, pretreatment for disinfection is a necessity.
I also heard that someone else found some down by a lake.
You do have to check the type of wood as somne will just rot in your tank.

There was a similar thread last week or so. Be sure the wood you find is good and hard. Wood that breaks or crumbles without too much pressure won't last long in your tank. Also, though hydrogen peroxide might kill the baddies, boiling the wood (repeatedly if necessary) will help keep it from floating (without having to attach it to a hunk of slate).

I've also looked at new house construction areas - they often have trees turned over and left it for weeks if not months, hence dead. I snapped off few pieces near the root that looks nice and boiled and left soaked for over 2 months until all the tannin are out.

So far, all fishes seem to like it...