I would expect it to be something like this.
Introduction:
Explain the purpose of the article and what you hope the reader will get from it.
Buy or Build:
Buy - Explain the advantages and disadvantages of buying a Pre-Built computer.
Build - Explain the advantages and disadvantages of building a computer.
Pre-Shopping:
Explain all the options involved in various system configurations. Explain the basic purpose of each component and what to look for (good and bad).
Shopping:
Explain the Shopping experience. Combo Deals, Free Shipping, Rebates, Reputable Outlets, Store Reviews, etc...
Post an AMD and Intel Build - low,medium and High range PC.
Assembly:
Cover all the possibilities, Lots of Pictures (a GOOD camera is needed), Videos are really helpful but not every user has broadband and some people just need things to be done slower. So a video will be an addition to a written explanation with pictures. This will be the hardest part.
Bios:
Explain the basic knowledge required to make changes required for proper operation. How to check your CPU, Memory and HDD settings, etc...
Installing an Operating System:
Run through the Basic Procedure, Screenshots.
Drivers, Windows Update, Recommended Software:
Explain why drivers are needed (basic) and where to find them.
Explain why it is important to keep the OS updated.
Recommend additional software like anti-virus and explain why it is needed
Special Considerations:
Links to various guides that maybe helpful (as an example, the SSD Tweak Guide).
Troubleshooting:
Explain basic Troubleshooting Procedures. Resetting the bios, Memtest, cabling, etc...
Explain How to Post a Request for Help and what should be included in the post.
Benchmarking and Monitoring your new system:
Explain basic benchmarking, as in checking for proper system performance and not record setting. Explain how to Monitor the system temperatures, fan speeds and basic voltage readings.