Buy a good tripod (like Gitzo 1325) you will not regret.
Black Card is just any card board that is black in color and big enough to cover the diameter of the lens, it is normally use to create effects or cut down some unwanted lights or reduce vibrations caused over the exposure time. The technique is usually used for taking fireworks in bulb mode.
When you are ready to take an exposure, hold a piece of black card in front of the lens, making sure you don't touch the lens. press the shutter using a cable release, then wait a few seconds for the vibrations to die down then quickly move away the card and replace it again 1 second later with the card still in front of the lens, close the shutter. I would recommend repeating the same exposure a few times in the hope that one is sharp. You should also take more exposures at different exposure times, just to make sure that the correct exposure has been given.
