A good way to start is to download templates from the Microsoft website. They will allow you to modify their templates according to your preferences, but they'll also offer an easy way to make your own. Using Microsoft Word, you can make your own label templates, quick and easy. If you look at the top and on the edge, you'll see some measurements. Those measurements will help you gauge the location of the label parts. Move them around and try them out, change fonts or locations, add pictures and so on, and once the label looks like you want it, click File, Save As and select Word Template. Under File Name you can give it the name you want. Click Save to save your modifications. It's as simple as that. You can create as many templates as you want, and all of them will be stored in Open Office documents.
Why create one? _ "Re_inventing the wheel", is no fun. If you work for a single organisation it's likely that your templates could last a long, long time with no need to go back to the design board every time you are asked to create a new manual or user guide. When you work for yourself it's a great way to show clients that you have the skills they are looking for without breaking any confidentiality clauses with your existing clients, and with just a little bit of luck they'll adopt your method of working so you can continue to recycle your past efforts too.