What should the resulting articles look like?

We care about your blog to not change its look and feel, therefore we want you to write your article in the same form and style you always do. If you normaly add images, we are happy about images – if you usually never add images, you should not start doing it for us.
Also, the length of the article is your choice: If the topic is done with 200 words then that is just as good as writing 1000 words.