Chris Pearson is one of the premier WordPress developers. He understands WordPress as well as anyone- and he has a post on his site that everyone should read, here is an excerpt:

categories are a powerful tool that bloggers can use to exercise precise control over content in a dynamic environment.

Unfortunately, the true power of categorized content has been masked by the one size fits all implementation you see everywhere on the Web—the proverbial long, ugly list of category links now appearing on a blog near you.

As luck would have it, that awful category list also turns out to be a very poor presentational strategy for your site… But why?

Why Your Category List Isn’t Doing You Any Favors

By giving users a list of categories to browse on your site, you are creating a psychological conundrum that usually leaves them with a severe case of analysis paralysis. This is a condition where users, when presented with too many options, end up selecting nothing at all.

Being presented with more choices, even good ones, can hinder effective action. In one study, doctors couldn’t make a decision when a second promising drug showed up.

— Fast Company, November 2007

Counter-intuitive? Maybe. Human nature? Absolutely.

Whether you’re selling products, writing copy, or designing interfaces, you can benefit from playing into basic human psychology. And interestingly, with Website categories, accommodating natural human behavior also turns out to be an excellent SEO strategy

Automated SEO and Content Management with Categories

At first glance, it seems convenient that WordPress automatically creates category pages, tag pages, and just about every other type of page you can imagine1. Dig a little deeper, though, and you’ll find that this form of page bloat is a remarkably poor site-building practice—it’s a condition that should be avoided whenever possible.

As far as blogs are concerned, categories are the single biggest contributor to both page bloat and link dilution, two of the most abominable SEO sins. Ironically, when used properly, these same categories hold the key to efficient, automated site optimization and content management…

The difference, of course, is all in how you use them. Armed with a bit of knowledge and a few lines of code, you’ll be able to use categories to:

display content however you like, wherever you like

link directly to interior pages—not to interstitial “bloat” pages like monthly archives or category archives

provide your users with a smarter, more intuitive way to browse content that may be of interest to them… read the rest at:

What Every Blogger Needs to Know About Categories — Pearsonified.

I like to think of Categories as the table of contents to your site (in this metaphor- tags would be the index)- they are there to help a reader find what they are most interested in, and to group posts of a similar nature.

They are also a powerful tool to refresh old content in Google’s eyes- by collecting old posts with new posts Google sees the category as a new mix of keywords every time you add content to a category.

We can also use categories to present information in different places or in different ways if we want, but for the most part, they are a critical component of navigation. Read Chris’s whole post to learn more.

Found an excellent article on WordPress as a Content Management System- and much of it agrees with what we’ve been preaching and teaching for the last couple of years. It is well worth jumping over and reading the whole thing.

The key for us is how easy it is to use WordPress- as compared to other CMS systems. The author of the following article also said the same thing:

I just know WordPress, and I know it is easy to use (as opposed to, say, Joomla) for not so familiar clients. Add a solid support for “static” content, being the WordPress Pages, and more newsy update flows controlled by the Posts, and you’ve got your needs pretty much covered for most websites online today.

If you can’t use it yourself, and keep your company on the forefront of Industry news and trends, you don’t really have a website. We also see the terrific value WordPress offers as an Search Engine Optimization tool. Use WordPress right- get to the front of Google.
Here is his very helpful checklist:

Checklist for Creating Web Sites with WordPress as the CMS

These are the things I tend to think about before choosing and designing a website where WordPress will be used as the CMS. There’s probably other things as well, things I just haven’t take into account since my clients haven’t had that kind of need yet. Feel free to add yours in the comments, sharing is caring after all.

* Is there even a need for a CMS for the client?

* Is WordPress the correct CMS? Will it fit the needs? Is the translations available for the WordPress backend good enough? How will it be upgraded?

* Will I need to extend WordPress using plugins? Are any hacks to the core necessary, because if they are, how will I make sure that these won’t break when the core is upgraded?

* What types of content will there be, and what should be deemed static (i.e. use Pages), and what is flowing updates (i.e. Posts)? How will I present this, and what is the main type of content?

* How will the permalink structure be? Should it really say “category”, why not “view” or “updates” or something else?

* Will the menu be static (i.e. coded into the theme) or controlled by WordPress (i.e. listing using WordPress tags for Pages and categories)? How could this go wrong in the future?

* What hierarchy will the Pages have? This is important for the URL, since it should be coherent with the menu hierarchy after all.

* How will I present sub-pages (i.e. Pages having a mother Page)? Should there be any at all?

* Do I need Page templates for various sections? How will these work with sub-pages?

* What categories will I use? Should the client be allowed to create new categories?

* How will I present Posts content?

* Do I need category templates for the various categories?

Things To Consider When Using WordPress as a CMS | Devlounge

Although he asks for comments on this post- they don’t seem to have them- but I would add that the issue of using Categories and Tags are still a little fuzzy for most people.

Think of Categories as the table of contents of a book and tags as the index- and you are track to better understanding how they should work. All of his points really don’t apply to people using off the shelf themes- which are the jack of all trades solutions for the most part. To really optimize WordPress as a Content Management System, you are really talking about custom theme development.

We’ve just completed an implementation of WordPress as a CMS on www.girlfriendology.com, head over and take a look.

Someone said on the hackers forum: “The analogy I use is that Categories are like a book’s table of contents, and Tags like its index.”

However, be aware that categories that are actual search terms are very strong Google magnets.

So, instead of using a category “lines we carry” think about “High Performance Motorcycles in Dayton OH”  and then use tags to highlight the brands and product names.

Tags are ways to identify the keywords or concepts in each post- categories group the posts in ways that make sense for others. Lately, Google has started dinging sites for putting a single post in more than three categories (which is too bad)- so think carefully about your choice of categories.