Content controls allow you to have fixed lockable areas in which to input information without affecting the rest of the document and should be considered. They are also more practical then legacy form fields, especially for data extraction, and do not require the document to be protected.
For ease of insertion see
https://www.gmayor.com/insert_content_control_addin.htm. However I have been working on a major update for a few weeks. It is almost completed and is in the final stages of testing. It adds editing facilities and a number of other useful functions for template creators. I hope to have it on the site over the weekend. If you would like a preview copy, contact me via my web site.
There is a lot more in depth information about content controls on Greg Maxey's site -
http://gregmaxey.com/word_tips.html .