This sentence, at the beginning of an article is essentially part of the thesis. If I am advancing an argument, I will begin here by stating my thesis and setting the tone for what is to follow. Throughout the remainder of the article, I will introduce you to the basic structure of an article that is meant to persuade or inform, and hope it will make your articles a little more coherent.
Following the thesis is the body of the article. Pretty much anything goes within the body, but the basic content should be to support the thesis. If you are all over the map in this part of the article, it is here where you are likely to lose your audience and/or invite "red herring" responses that meander all over the map, but, essentially, accomplish nothing (except for point whores who gain a few points through them; however, it is not even a good point whore tactic as, once you have established a reputation for such meandering, you will gradually lose your audience). This can be as many paragraphs as you'd like, but the basic theme should be one of supporting the thesis.
This is the conclusion. This is where a nicely written article gets all wrapped up and can often be accomplished by simply restating one's thesis in other words. Now, granted, the rules change for a rant, but again, it would get a little tiring if all we ever read of you gave us the conclusion that you had been a little too intimate with Mr. Daniels over the last couple of hours.
Best of luck and happy blogging.
Signing off (tongue firmly planted in cheek),
Gideon MacLeish