Hi Carl,
Is it the making of a style guide or the using of a style guide that is troubling you?
Making it should be really easy because you said you already have a document that has the formatted styles you want to use ... make a copy of the document, name it uniquely, delete all existing text, write a paragraph of instructions/description, and finally create a list of the unique styles formatted with their style setting. Below is the first 2 page sample from one of ours.
We apply the style guide programmatically to new documents being created or existing documents where we want to change the styles.
If you want to follow this same approach, you can use our AuthorTec Styles Update add-in, it's free but you have to build your own styles. :-) Search that name and you'll find info about it.
Since Quick Styles was mentioned by someone else, we also have a free add-in called AuthorTec Quick Styles that helps get that Word function working the way it should.
Hope this helps