I can tell you my way. It is important that you do something you really like, so you're passionate with it too. Then I would maybe think quickly what to include and write the structure down more or less. Then it is time to go on research. Make sure your information is correct and use several sites not only wikipedia. You may also go to the library as well. Maybe you realize then, that you have forgotten something in your structure, so update it if necessary. Afterwards comes the writing part. This is actually the easiest and probably the fastest part too if your research was well carried out. Make sure you write those things that you want the reader to understand and to actually read and avoid senceless phrasing. Quality not Quantity is important or Content is King as it is said in HubPages. In the end, I would read it through for any typos.
I hope I could help you with this.