This is a rehash of a few points that have been brought up here and there about these. As a general rule, these are acceptable (and even pointed out in the /faq page). I don't think SharePoint has any particular reason to disallow self-answers.
Treat it like a Question
Always make sure that you're asking a question. It gives a better sense of functionality when a self-answer's only distinguishing factor from the rest of your question base is the fact it was self-answered. If it is significantly different in structure and operation, people get the impression that it is supposed to be a completely different class of question. I rather suggest that it should not be, and should be a question like any other.
Don't skimp on Question Quality
When you actually need an answer, then you're probably going to be courteous about details. That way, answerers understand the situation better and are more likely to help. If you already know the answer, however, one might skimp on similar level of detail with the question. Don't.
Be Open to the prospect of Other Answerers
Remember that this is a community site, not a personal blog. Articles are nice but a lot of people like to participate for a variety of reasons, from reputation to feelings of satisfaction. The reason doesn't matter, the point is that people like to participate. So be open to the prospect.
Be open to the idea that someone could post a better answer. Don't ask under the impression that you're going to be the only person with something to say. Perhaps you might even consider phrasing the question in a way that you can attract other people to contribute towards crafting an even greater store of knowledge.
And on the same note, a lot of people suggest waiting for a period of time before self-answering. That is, post the question and then do not post your own answer until after, say, 24 hours. This gives the rest of the community ample time to post their own answer, and you might even find yourself with an answer so impressive you won't have to self-answer anymore.
Exercise Moderation
Again on the community point. Just make sure not to make an extremist habit of it. You have good traffic but people will get leery if the front page is dominated by a single user proselytizing their work. Or it may give the impression that the site is all about self-help and not about users helping each other. Both of these contribute to a basic idea that one should be cautious and not post too many self-answering questions overall.
As long as you serve the effort to ensure quality questions, the fact you're self-answering is fine. The salient point is that we have the information on our site. If the only option to get it on our site is by self-answer, then by all means go ahead. Just remember the above guidelines, they'll make an otherwise mediocre self-answer into a stellar question worthy of showing off to people who visit the site.
