Style guides are just that, guides or guidelines to maintain a particular style of presentation. Guides instruct on correct usage. They are essential for maintaining consistency of an organizations and brands presentation across various media. Because of a proliferation of media, as well as media-specific goals on the Internet (aka search and social discovery), style guides have increased in importance and complexity. I prefer to include technical detail in style guides as it can help provide information that makes all the difference in achieving the implementation and ongoing relevance and adherence to the desired style guide.
Complete Set of Style Guides
Jump ahead if you are looking for something in particular, otherwise the discussion continues below. Note: these style guides are incomplete and in-progress (continually) - Contact information - Identity style guide - Image style guide - Social Media style guide - Usability style guide - Video style guide - Writing style guide
Background and Discussion
There are a variety of style guides for brands and organizations (that is, organizational brands and brand brands). The most well-known kind of style guide is a writing style guide, including punctuation, English preference (American, Commonwealth, etc.), voice, capitalization, place names, etc. However, corporate or brand style guides are now well known in terms of basic brand imagery, colors, typography, logos, etc. Beyond that we can focus on things like image style guides, video style guides, as well as usability style guides.
Brand Style Guides and Organizational Information
Style guides are internal information which help shape both internal and external communication and as such are a part of corporate communication. I taught many semesters of Organizational Communication courses at the university level and found Paul Argenti's take on it the most comprehensive and clear, from a single source. Unfortunately his book Corporate Communication is ridiculously expensive, and to be frank I haven't looked at it in 10 years, so who knows if we've fundamentally changed as a species (likely not). The third edition worked for me, and one can pick up a copy for about 0.01 USD + 5.00 USD shipping on Amazon. Just be sure to supplement with a reasonable approach to social media and Internet marketing in general. For the more academically inclined, he has published over the years as an academic.
Style Guides and SEO Guides
Modern style guides, as intimated above, need to be aware at a fundamental level of the search and social optimization requirements. This needs to be baked in and can also provide useful information as to not only the how but the why in terms of style choices and adherence to guidelines.
Style Guide-Driven Development (SDD)
There is even now a thing called Style Guide-Driven Development (SDD) which basically helps a designer and developer out quite a bit, as generally shrinking the design exploration space is a huge help when trying to get something done. I would suggest even more so, that a styleguide acts as a strategic as well as tactical guide (though it can also be informed by strategy, and thereby evolve incrementally or evolutionarily. All device and interface development as well as any new initiatives should be informed by style guides at various levels.
Style Guides and Web Design and Redesign
Brad Frost makes a compelling argument for style guides in terms of web design. He has a slightly different list, but makes pretty much the same argument in the following video:
List of Style Guides
I'm going to put my style guides up on the web. This is normally something closely held, but it may help others and frankly organizational change is normally so difficult. Even if someone were giving out gold, if only an organization would change its business process and workflow, most organizations would be too hidebound to take advantage. The first on our list of style guides is not a style guide but core metadata of an organization, namely an identity and contact guide. After that the normal identity/brand style guide, writing style guide and other issues. Note: these style guides are incomplete and in-progress (continually) - Contact information - This has basic textual information in terms of names, numbers, addresses and the like - Identity style guide - This is the core brand persona in terms of names, logos, colors, typography, as well as taglines, basic brand and/or organizational values and goals - Image style guide - All images, diagrams, figures, including photography guidelines - Social Media style guide - And we wouldn't be complete without a social media style guide. In this case how to interact on other sites that are generally social - Usability style guide - This sets the tone for tradeoffs between functionality, usability, simplicity, etc., and may include specific technologies or techniques - Video style guide - Guidelines for video production and the outcomes objectives - Writing style guide - All writing in whatever format (from brief text ads to complete manuscripts) Note that all style guides must be regularly revisited in the face of changes which are taking place within and outside the organization.