Database for Content - OK to store HTML?
Like others have pointed out there's nothing dangerous about storing HTML in the DB. But when you display it you need to know the HTML is safe. Seeing as you're the only one editing the HTML I see no problem.
However, I wouldn't store HTML at all. If all you need are headings, paragraphs, lists, links, images etc I'd say Markdown is a perfect fit. The benefit with Markdown is that it looks just like normal text (ie you could send your articles as e-mails or save them as txt-documents), it takes up a lot less space than HTML and you don't have to change it once HTML gets updated.
From the security point of view it is not less secure to store your HTML in a database than storing it anywhere else - if you are the only author of that HTML. But then again if other people can author HTML in your website then it doesn't matter where you store it - only how you sanitize it and how and where you display it.
Now whether or not it is an efficient way to store HTML is a completely different matter. If I were you I would use some decent templating system and store HTML in files.
Storing HTML code is fine. But if it is not from trusted source, you need to check it and allow a secure subset of markup only. HTML Tidy library will help you with that.
Also, you need to count with a future change in website design, so do not use too much markup, only basic tags. To make it look like you want, use global CSS rules and semantically named classes in the markup.
But even better is to use Markdown or another wiki-like syntax. There are nice JS editors for Markdown with real-time preview (like the one here at Stackowerflow), and you can avoid HTML altogether.