You need a hammer, 1 cup mayonaise(for fork oil), bearing grease pack(JB Weld) and an auger.
First you need the parts. Get anyting. It doesn't really matter. All bike parts are equally and totally interchangeable.
Find the fork, or suspension fork, if applicable. It is the springy thing with two legs and knobs all over. Put the steerer into the long verticle tube in the middle of the bike. What's that black lever thingy on the verticle tube you ask. Well that's a quick release my friend. You can remove your fork in seconds!!!!
Next. Install the crank. The bottom bracket is just a scam dreamed up by the bike industry. You won't need it. Throw it away. Find the "skewer". There will be two. YOu need the longer one. At the back of the bike are "dropouts". They come standard from the factory too far apart. You must bend them in to suite your crankset. The cranks go on either side of the outer frame. Don't be concerned with which to put on which side, it will all work out. Insert skewer, clamp skewer to correct tension, not too loose or you could hurt yourself if you plan to do FR or big drops. Don't forget to put the "cassette" in the between the dropouts as well, laced through the skewer. Voila! Cranks are installed.
Now you need a long broom handle. Most people are using aluminum these days on their bikes, but wood will do jsut fine if you don't need the bling.Insert it into the other end at the front of the bike. The "headtube" is what you are looking for. YOu can now install your stem and bars on the underside of the frame. Clamp the stem firmly to the broom handle. You may need shims. It doesn't need to be tight though so it's not a big issue. The broom handle is held on at the top side with the rear brake lever and shifter. THe "headset cap" threads into the broom handle at the topside to keep the things together. You can trim the handle to whatever drip length you prefer.
Next, install the bars and headset. Install half of the headset onto the center of the handle bars. Put the bars throught the BB shell and put the other half headset on the other side. Press the cups into the BB shell gently, you don't want to wreck anything!!!! The threads provide grip. Once pressed, you are Done!
Next, on to the pedals. THey are bolted to the front "dropouts" on the fork. The spindle threads are press fit into the dropouts. You may need to gently persuade them with the hammer.
That is pretty much it. Throw on the wheels, shifters, tire cables and housings, ashtray and brake rotors.
YOU ARE DONE!!!! Be sure to do the rest of yor work woth the bike in its proper riding position.
WARNING!! Don't forget to use JB Weld on all of your threads and any mating surfaces. JB Weld is also your friend when installing your chain too.

GOod luck and ride safe!!!