Creating categories that attract search engines

One little-known SEO tip for WordPress users: The names you give the
categories you create for your blog provide rich keywords that attract
search engines like bees to honey. A few services — Technorati (http://
technorati.com) being one of the biggest — treat categories in WordPress like tags. These services use those categories to classify recent blog posts on any given topic. The names you give your categories in WordPress can serve as topic tags for Technorati and similar services.
Search engines also see your categories as keywords that are relevant to the content on your site. So, make sure that you’re giving your categories names that are relevant to the content you’re providing on your site.
If you sometimes blog about your favorite recipes, you can make it easier for search engines to find your recipes if you create categories specific to the recipes you’re blogging about. Instead of having one Favorite Recipes category, you can create multiple category names that correspond to the types of recipes you blog about — Casserole Recipes, Dessert Recipes, Beef Recipes, and Chicken Recipes, for example.

Creating specific category titles not only helps search engines, but also
helps your readers discover content that is related to topics they are inter-
ested in.
You can also consider having one category called Favorite Recipes and creating subcategories (also known as child categories) that give a few more details on the types of recipes you’ve written about. (See Book III, Chapter 7, for information on creating Categories and child categories.)
Categories use the custom permalink structure, just like posts do. So, links
to your WordPress categories also become keyword tools within your site
to help the search engines — and, ultimately, search engine users — find
the content. Using custom permalinks creates category page URLs that look
something like this:

http://yourdomain.com/category/category_name

The category_name portion of that URL puts the keywords right into the hands of search engines.