For a one-stop shopping summary, see Summary of arguments in favor of two spaces between sentences, a short outline I wrote to further a twitter discussion. When I finally write up one comprehensive article, this may be the outline for that.
Real evidence in favor of one space between sentences is lacking, being based mostly on myths, and this blog works to discredit those myths. One of the first pieces I wrote for this blog, Everything You Think You Know About Sentence Spacing is Wrong, gives an overview argument against several of the popular myths. Many of these are examined in more detail in other articles. The myth that wide spacing was created for the typewriter is covered in in detail in One or Two Spaces After a Period? How about Three?, which also covers the myth that monospaced fonts need more space. This is a followup to an earlier article, 19th Century Typewriting and Handwriting Rules, which discusses how standard wide spacing once was, and hints at the issues covered in the later article.
The myth that modern fonts "fix" sentence spacing is covered in The Magic of the Modern Font, and the myth that wide sentence spacing creates "rivers" is covered in A River Runs Through It. This article also touches on one aspect of how the Linotype, a new and highly industrialized printing system introduced in 1886, affected typography and sentence spacing.
The Linotype is a common theme in this history, and one of its biggest roles is covered in Two Spaces - an Old Typists' Habit?, which explains how the Linotype dealt the final death-blow to wide sentence spacing, and also explains why many editors' love of monospacing is just cargo-cult worship of dead technology. A bit about the machine's earlier impact on spacing is covered in The Cost of Printing Errors on the Linotype.
Many people are misinformed on this issue from one single article in Slate called Space Invaders: Why you should never, ever use two spaces after a period, which like most other sources is a complete mess of myths and misunderstandings. I pick the article apart in my own review of That Slate Article.
Along the way I touch on some related issues. In Dynamic Sentence Formatting for Blogger I talk about and demonstrate how we can use the two-space habit to automatically format sentences to anyone's individual aesthetic. In French Spacing, I talk about the confusion that has developed over French and English spacing, with an update in The Horror of France. In Spacing in Twitter (a small victory), I take personal credit for a dramatic shift in Twitter's handling of spaces. And finally, a copy of a typography poem I found, in Type Was Made to Read.
And one final thought. The Chicago Manual of Style, the AP Style Guide, and others are industrial conformance manuals. If you don't work for these companies, following their style guides makes as much sense as looking to McDonalds for menu advice.