It's good to have you here to share my experiences of building My Super PC, here's what I do.
Select the components that you would like to be in your new computer. This is often the hardest part of assembling a computer, because there are many different computer parts on the market, and ensuring that all the parts are compatible with each other can be a time-consuming process. At a minimum, you will need a case, power supply, motherboard, RAM, processor, processor heat sink/fan, video card, hard drive, CD-ROM drive, network card and sound card. There are many other parts to choose from, such as TV cards, wireless cards, cameras and printers.
Find a clear area to work, such as a large table. Carpeted areas should be avoided, due to the chance of static electricity buildup on your clothes.
Install the power supply into the case, if they came as separate components. Secure it using the four screws provided.
Open the motherboard and line it up to the expansion slots at the back of the case. Place standoffs into the case at any point where a screw hole in the motherboard lines up with the standoff slot in the case. Secure the motherboard with screws, and connect the proper lead to it from the power supply.
Install the heat sink and fan assembly over the processor, with thermal grease in between them. Immediately hook the power lead from the fan to the motherboard.
Slide the RAM into the proper sockets until it clicks.
Mount the hard drive and the CD-ROM drive into the case. Connect the IDE or SATA cables to the motherboard. Connect a cable from the power supply to each drive.
Install the sound card, video card and network card into the PCI, AGP or PCI Express slots. Connect all the cables they require.
Connect all external components, such as the keyboard, mouse and monitor.
Boot the machine and install an operating system.