For basic blog operations, you do not need to know HTML or CSS, however it is based on the theme's HTML structure and CSS provided, so if you want to tweak these.. then it would make a lot more sense to know the basics of XHTML/CSS. Installation of the WordPress can either be a one-click install based on your hosting.. or you have to upload the files.. and run the database config and account information.
For your ads, usually the ad provider gives you code that you can copy and paste, so no big need. But it will make it easier as you will have to either define this inside the theme template code... or have a plugin that handles the ad code.
For e-commerce, there are fairly simple open source ecommerce solutions, but many of them.. to fully integrate it into the site, you will have to know some programming. However ones like PayPal.. you fill out the product information, and they provide the HTML code for the button. From there, just insert the code into the site.
It would be best for you to learn basics of HTML and CSS. This is the base structure of all web sites.. and will make it easier to maintain your WordPress sites.
w i l z d e z i g n ... XHTML, XML, CSS, ColdFusion, PHP, SQL.. hand coder only!