Now log into your WordPress site and activate the plugin. Locate Plugins on the left side of the page, and click the black arrow to the right of Plugins. This will reveal the two options for plugins. Click Installed. A listing of installed plugins will appear on the right side of the page. Find the plugin named “WP Shopping Cart” and click activate. If using WordPress Multiple Users, you could alternatively activate the plugin site wide. Note: I personally have had issues activating this plugin site wide. I have, however, enabled the ability to activate plugins at the user level. Also, if you run into a problem installing this plugin due to not enough memory, you might have to contact your web host for assistance in update the amount of memory through PHP.
Once activated, a Products menu will appear on the left side of the page. This is where the ability to add products and pricing takes place. The settings link under Products is the first step you will want to do since you will want to setup a base country/region, as well tax settings, language and currency type prior to adding in any products or categories. If you are in the United States, like I am, you will want to select the United States (obviously) and the state you do business in. This will allow you to set the taxes for the location you are in. You can also set the tax rates for any other states you physically do business in or are required to collect tax in (check with your local government for this).