Hey..
Facebook pages and groups are best way for promotion.  Whether you are trying to promote a particular product of are trying to brand yourself, you should have a facebook fan page.  It's a great way to build a list and also meet others online to work with. If you don't have a fan page up yet, try putting one up now. It's easy and free.  Then you can put one of those 'Like' buttons on your blog or website.

Create a fanpage and be active on it daily.
Increase your Fan & friends network
Post interesting post on your fan page to get more likes.