bog wood, malysian wood, african wood - as long as it is labelled for aquarium use, it will be fine.
you can just rinse the wood and put it in the tank, or you can boil it, or you can boil it and soak it for several days. most wood puts out tannins, which will discolor the water as if you've poured a pot of tea into the tank. it's not harmful although it may lower your Ph a bit. the more you boil and soak the wood, the more tannins will come out before it goes into the tank. it's up to you. if you want it in the tank asap, water changes and carbon will help remove the color. keep in mind though that a lot of fish species from blackwater rivers (south america and aia as well, i believe) will do fine in the darker water. it makes lighting less harsh and allows flourescent colors (like on neon tetras) to really pop out.
