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.
Before you start looking online for a sample proposal template, you need to have a basic idea of what you need. This will help you to sort through all of the different templates and find the one that is going to suit your needs the best. Once you have downloaded a sample you will be able to create exceptionally professional looking proposals that can help you win more bids keeping your company operating in the black.