Add the Wordpress categories block to the same page you have set up as the main blog. Click on one of the categories that you set up. The example below is the using the page name blog in concrete5 to display the main blog content.
When you click on one of the categories you will see that the url will change to the url for that category.
The display of the url will vary depending on how you set up your urls in wordpress. Once you click on one of the categories it will forward you to that page and look something like this.
If you want to set this link in the main part of your nav then add it to the site map as an external link. Name the link the same name as the category.
http://www.domainname.com/blog/...
When you click on one of the categories you will see that the url will change to the url for that category.
The display of the url will vary depending on how you set up your urls in wordpress. Once you click on one of the categories it will forward you to that page and look something like this.
http://www.domainname.com/blog/?category=4...
If you want to set this link in the main part of your nav then add it to the site map as an external link. Name the link the same name as the category.