Digital document design has become much more then just aesthetics and it is now important that a document can be read by "robots" as well a people. Robots, or crawlers or spiders, are another name for indexing services that search engines use such as google. As you are well aware, search engines are the way people find most things on the web today. Most people assume that search engines use hidden meta tags to index web pages for searching. This may have been the case in the early days of the web, and is only partially true for a few search engines today. Search engines are now programmed to look at the text inside html tags that are used to design a web page. Weight is given to the words depending on which tag they are in. This is how Search Engine Optimization, or SEO, relates to document design. I will discuss the tags that are important to making your site search engine friendly, and some ways to keep the design you want.
First off is the title tag, this should be descriptive as to who you are and what information you are presenting in your page. The title tag should also stay short and not be greater the 60 - 70 characters. Keep in mind that the title tag is not only something that search engines use to find keywords to your site, but it is also what the user will see in their search results.
Heading tags are also regarded as important content, as they are meant to be headings on your tags. Designers often use images as headings, but these will not only require descriptive alt attributes, but also are weighted very low by search engine crawlers. Cascading style sheets (CSS) can also be used to design headings, but be when using CSS make sure to apply your CSS to the heading tag and not to another block element tag, like span or div.
Make sure to use descriptive keywords in your ALT attribute for your image tags. This will help search engines that index images as the image file name is not always relative to the picture. The alt tag is included as body text by most search engines, but as mentioned previously is weighted low.
Meta tags are still used by some search engines but are weighted very low due to over use. For the Meat Description tag, it is best to keep it under 100 characters. The meta tag is also important because it is displayed in the search results. For the Meta Keyword tag, it should be kept under 250 keywords, and should not contain any words that are not in the document.
As mentioned previously search engine crawlers can not index images, this is something that many designers have problems with for a few reasons. First text is difficult to control, even when using CSS to format it. The user must have that font installed, and the user can increase and decrease the font size in their browser easily. Images solve these problems for a designer because they can not be changed, but images will hinder its search engine optimization.
The last and probably most important part of search engine optimization are links. I will referrer to two different types of links, internal and external. Internal links are things like menus and site maps. It is important to have at least one static link to every page on your site that you want indexed. This is so the search engines know how to get to every page when they spider or crawl your site. External links referrer to other sites that link back to yours. This is another way that search engines rank your site. This is unrelated to design so there is no need to go into any more detail about it.
As with everything, there are people out there that abuse the system, so search engines have put measures into place to not rank these types of sites highly. Some things I have already mentioned like number of characters in title and meta tags. One additional thing to be careful of is to keep the number of links on one page to under 100, more than 100 links we be thought of as spam. For a large site map it would be a good idea to split it up into multiple pages. Another thing to be careful of is using the same words an excessive amount on a single page. This is a common practice for people trying to trick search engines.
Currently there is a battle between designers and search engine optimization people. Both are important elements of marketing your site and your business on the web, but they have contradicting requirements. As discussed many design needs are not SEO friendly, and many SEO needs are not design friendly. Make sure you find a good middle ground when designing your site.
References:
How can I create a Google-friendly site?
Webmaster Guidelines
Search Engine Optimization Standards and Spam Discussion
Google SEO Basics for Beginners
Media College.com SEO Basics
Google Rankings Basic SEO advice
SEO 101 - Basic Optimization Techniques
