Because newsletter templates are available in all variety of lengths and sizes, there is really no limit to the content that you could potentially write. Keep in mind, however, that you should probably keep down your word count to a level that people are comfortable reading. While you may think everything that you are spouting off is fascinating, it's helpful to first sit down and make an outline of what you want your main message to be, or what the major news is that you are trying to share.
Crafts Sites. For a broader category, craft sites are the next best places to find templates. This is broad in a sense that they have listed sites for different types of arts and crafts like beadworks, candle making, and ceramics. Not all these do_it_yourself sites can literally hand out free templates, but will give you enough inspiration and idea to creating one. But it is best to browse on categories like drawing, gifts, paper crafts, patterns, or rubber stamping. Scrapbooking is also under this category.