The very first thing to do when considering building a PC is to make a solid plan of action for yourself such as choosing the correct parts and setting aside the time (more than you think) to work on your project. Things you will need to do include: the gathering of all the necessary tools and finding a proper non metallic surface area to work on prior to proceeding with your project.
A lot of wasted time and effort can be avoided by preparing for what you are doing and making sure you have everything you need before you get started. An ounce of preparation equals a pound of cure which means if you are well prepared you won't have to put out a lot of additional effort to get your project done with by chasing after things you forgot. Remember to always work in a well lit moisture free environment with rubber soled shoes preferably to cut down on static energy displacement.
Having a non metallic work surface such as wood will also help in the prevention of lost parts due to static electricity that can be created by two metallic surfaces touching one another. Another important part of the preparation is having a grounding (Anti-Static) strap attached on your wrist and grounded out on the computer whenever you are handling any of the system parts to further minimize the chance of shorting out your system hardware. This can be a costly lesson to be learned the hard way.
Read the manual that comes with your motherboard cover to cover as this is a very important step in familiarizing yourself with your motherboard which is essentially the heart of your computer. Get a relaxing drink, then read the manual again. The manual can explain most of your hookup questions if you look close enough inside of its covers. Make sure you have all of your parts laid out and ready to go along with all of the software you will be using in your system building project this will make the assembly process go smoother. Put the cat out, take a deep breath, and "let's get dangerous."
Case with correct power supply
CPU and Cooling device
Video Card (If Applicable)
Sound Card (If Applicable)
Network Card and/or Modem (If Applicable)
CD / DVD Player
1.44 Floppy Drive
Pliers (Preferably needle nose)
Zip ties (Optional)
Preparation (start here) The Elusive Zen of Motherboard Identification