The rough black surface on your skateboard which keeps your board glued to your feet while you're pulling off skateboarding tricks. It's really only sandpaper with an adhesive so you can apply it to your board.

You can usually get the shop you bought your deck from to put the griptape on for you, but if you can't this is the best way to get a nice finish:
1. Get your griptape and get someone to hold one end (still stuck to its paper) at one of the kicks, then roll it out along the length of the board to the other kick. Push it down so you can tell just how much you need, then mark the length with a pencil. Cut off the excess (use scissors you either don't mind if they get stuffed, or are meant for cutting rough things) and put it aside, it is good to keep.
2. Remove the paper and begin sticking it down onto the deck. Make sure you start with the tip of one of the kicks (don't worry about the overhang for now). Careful not to get air bubbles trapped in areas, smooth it down from the inside out.
3. Now grab that pair of scissors again. Start cutting away the excess, getting as close to the edge as you can. You won't be able to get it right down to the edge, but don't worry about it. Now you need to go grab a file (not a nail file) and file away at whatever excess is left. Also file it at a 45 degree angle so you can see a thin line of the deck around the edge, this should prevent fraying.
4. (optional) Using a stanley knife, cut the sickest design you can think of into your griptape. I usually cut either my tag, Big Alba, or Dragon Ball Z into it, but you can do whatever you want. I've seen some go all out and cut dragons and tigers into their griptape which look like they were drawn in Ancient China, so let your creativity flow!

While Big Alba's technique will certainly work, it's certianly not the easiest way to go about gripping a new deck. The method I (and many, many others) use requires less tools and gives a cleaner edge. Trust me, this was my job for awhile and I did this at least seven times a day.

Because Big Alba has a step to figure out the length you need, I'm guessing he/she had a roll of grip tape. This is actually fairly rare. Only shops tend to have a roll of grip, and it's usually the generic kind. Most companies sell their grip tape in sheets that are about 1 to 2 inches larger than a deck. Take my advice and spend the extra dollar or two to get Black Magic or something similar. Ok, now how to get that sheet onto your board.

Materials:

• Screwdriver - You should have this laying around if you're putting together a board anyway. The grip will eat the edge of the screwdriver, so if you're going to be doing this often I suggest using one you don't really care about.
• Razor - Just a plain razor. Utility knives and the like are to expensive to ruin by cutting grip tape. (And this will ruin the blade) Plain razors are cheap and tend to cut better. Please don't use scissors. It won't make a clean cut at all and it ruins the blade.

Method:

1. Set your deck on a stool or tabletop. I prefer a stool because it's much easier to rotate the board on. Just make sure the edge of the board can hang off.
2. Go ahead and take the paper backing of the sheet of grip. Now, with a little bit hanging over the edge, stick a bit of the grip tape to the tail or nose of the deck. (Either one, it's just easier to work from end to end instead of from the middle out.) Pull against the grip tape with one hand, and begin smoothing it out with the paper backing with the other. (Using the paper saves your hands. If you have to do this much, you wouldn't have much hand left.) Go slowly and continually rub the paper backing back and forth to push out air bubbles. Continue until the entire deck is covered.
3. (This is the secret bit.) Take the shaft of a screwdriver and rub it around the edge of the board. Do it about three or four times. You should end up with a rectangle of grip tape with a perfect outline of the board inside of it. (What this is for is the weaken and thin the tape around the edge, plus gives you a perfect outline to cut around.)
4. Take your razor and from underneath the grip tape poke the corner through. Angle the razor back about 45 degrees and kind of "lean" it into the deck a little bit. Begin cutting by just sliding the razor along the edge of the board. If you rubbed the tape well with the screwdriver it should be like butter. Some people move the razor around the board, while some prefer to move the razor very little and rotate the board. Either one is fine. Cut all the way around the board, and if you're really good you can get the whole thing in one cut.
5. Rub the screwdriver around the edge on last time to push it down. Use a screwdriver or a nail to pop through the grip tape to make holes for the bolts. There, now you're done.

It's a good idea to scrape a line or cut a design (some companies have pre-cut designs in their tape) into you're grip tape to show which end is the tail. That way you can quickly glance down at your board know which way it's pointing. Enjoy the pop and grip of your new deck!