I would be more inclined to recommend a flickr account versus a facebook. There’s a misconception that anyone posting their photography on facebook is “in the biz” and you might get people coming to you, undermining any value you may have and asking for free photos. That’s fine if you can screen them for clients you actually want to portfolio build with, but ultimately if you’re not really ready to put yourself out there like that, just hold off.
The reason I recommend flickr is because it allows you to maintain your exif data, it’s easily accessible and easier to share on forums similar to this one. It’s also a good way to organize your images without being too overwhelming. Facebook has too many ads and things going on in the background, plus it’s riddled with viruses.