Access your blog Layout > and click on the Add a Gadget > HTML/JavaScript, Image or AdSense > in the sections Post ADS 1 and Post ADS 2.
Example:
ADS 1 Shortcode: $ads={1}
$ads={1}
ADS 2 Shortcode: $ads={2}
$ads={2}
INFO: After adding a Shortcode apply the Bold style.
