I follow the same path as Alex. The tools are free (other than Word) and there are many resources on MobileRead to help you.
If there is a person in your organization that works with the website, their html skills will be of great help.
My workflow is:
1. Create the document in Microsoft Word, using only the stylesheets for formatting.
2. Save the document as a filtered web page.
3. Import that file into Sigil.
4. Clean up and create the epub file in Sigil.
5. Convert the epub file to a mobi file using Amazon's Kindle Previewer. This creates the file for Kindles.
This is just one of several workflows you can use, but it is a simple, inexpensive, and efficient method to create ebooks.