I don't know of any templates, but its dead easy to make your own with Inkscape, or gimp. They're both free programs, just google them to find where to download them from. It took me about 5 min to make my first label, its nothing complex, but looks cool enough....
You could always google beer labels, find one you like, and change the wording on it just using paint if you wanted a label that looks like a proper beer label.