Here is an article from www.computershopper.com, explaining how to build a computer step-by-step. (I did not write this article, but citations will be provided to the original author.)
First, gather your tools. A Phillips screwdriver is essential, and needle-nose pliers and a small flashlight might come in handy. Place your case on a clear table, and remove the top. Drape all the cabling inside the case outside so you have room to work. Your case might have come with preinstalled mounts (or standoffs); John's and Sean's did. If yours didn't, or if you need to install more for additional bracing, compare the holes on your motherboard to the holes in the case to help you properly place the standoffs. Screw them into place, and tighten with pliers. The ports on your motherboard peek out the case's back through a removable rectangular panel called the "I/O plate." Punch out the preinstalled plate (it's incompatible), and snap in the one provided with your motherboard.
John's and Sean's cases came with power supplies already installed; Matthew had to put his in himself. Just slide the power supply into place, then secure it to the case's rear panel with the included screws.
We recommend installing the CPU, your RAM, and the CPU cooler onto the motherboard before mounting it—especially if you're using an oversized cooler or working in a cramped case (like Sean's). Place your motherboard on a sheet of bubble wrap or its antistatic bag, then unpack your CPU. For Intel processors, disengage the lever beside the CPU socket on the motherboard, lift the frame surrounding the socket, and remove the plastic guard. This is the LGA775 socket for your CPU—don't touch the 775 delicate pins inside! Next, remove the protective plastic from the CPU's bottom, and place the processor gently into the socket, parallel to the board. Match the arrows and notches on the socket and CPU; the chip drops perfectly into place. Lower the retaining frame gently, then re-lock the lever. If you meet resistance, don't force the re-locking—recheck the orientation and try again. Install the RAM next. Lower the plastic catches that bracket the two memory slots, then snap one module into each. (A bar in the slot and a notch in the module match up.) Make sure the catches engage the chips' sides. Now, for the CPU cooler. Sean and Matthew used coolers with the standard Intel design, which require you to just align the posts on the bottom of the cooler with the holes around the CPU and press down on opposite corners to lock the cooler into place. (Matthew's also came with an AMD attachment hardware, so no CPU is left behind.) John had to screw a provided mounting plate onto the cooler's bottom, peel and stick adhesive washers onto the fixed screws, and fit the whole assembly onto the CPU, guiding the screws through the board's mounting holes; he then had to affix washers and nuts to the bottom of the motherboard. John and Matthew needed to apply thermal paste to their CPUs before attaching their coolers; Sean's came pre-applied. A pellet-size dab is plenty; spread it slightly, covering the chip's center.
Maneuver the motherboard into place, fitting the ports through the I/O plate, and screw the board, finger-tight, onto the standoffs with the screws provided. If your case has a removable hard drive cage, remove it from the case, secure your drives inside it with the data connectors facing inside the case, then replace the cage. (John's Fusion case, on the other hand, had cushioned vertical slots for hard drives.) To install their optical drives, Sean and Matthew just had to pop out their cases' 5.25-inch drive bay covers and slide in the drives. Sean had to screw his into place; Matthew's case had a tool-free support system. Because they were Serial ATA (SATA) drives, no additional setup was necessary. John's case had a removable optical-drive cage in front of his power supply, and his drive used an IDE interface. He first checked that the jumper on the drive's back edge was set to "Master" or "Cable Select" so it would operate properly, then screwed the drive into the cage and reseated it. (Later, he had to wedge a spare washer from his cooler between the drive's disc-eject button and the case's to get the button to trigger.)
Both Matthew and Sean used PCIe x16 graphics cards, which needed to be installed in the longest of their case's expansion slots. Sean just had to unscrew the slot cover then press the card into place; Matthew's case had a tool-free system that held the card in place with levers. John also had a card to install: a PCIe x1 TV tuner that fit into the shortest slot on his motherboard.
Now, to sort out the interior wires and cables.
Your work inside is done. Now to the remaining cables.
Attach the PC to a power outlet using the power cord, then start it up with the Vista DVD in the drive, and follow the prompts. (You may need to direct the BIOS to boot from the DVD drive; watch the bootup sequence for the right key to press at startup, usually Delete, to enter the BIOS.) If you're using two drives, install Vista to the smaller one. Thirty minutes later, you should be at the Vista desktop. (For a detailed walkthrough, consult "Installing Windows Vista: A How-To Guide".) Before anything else, install the drivers and any additional software that may have come with your motherboard, case, or expansion cards. Congratulations! You've finished your build. A computer like Matthew's or Sean's is ready to go. John's entertainment PC, however, needs some additional connections and tweaks; read on to learn how to take advantage of Vista's Media Center. ” (Burek & Grevstad)
References Burek, J., & Grevstad, E. (n.d.). (J. Burek, & E. Grevstad, Eds.) Retrieved 03 17, 2014, from Computer Shopper: http://www.computershopper.com/feature/how-to-build-your-pc-a-step-by-step-guide