This plugin adds up to four new buttons / links to the WordPress Editor panel. You can select to add a quicktag to easily insert: 
Amazon item links 
Amazon product searches 
custom span class 
custom div class
The settings pane allows you to enter defaults, as well as your own Amazon associate ID.

David’s Ultra Quicktags

Adds new buttons to the Editor window (Amazon Links, Amazon Search, etc.).

Shawn Hayes

This plugin allows you to add useful quicktag buttons to the Text (HTML) mode of the WordPress WYSIWYG editor. There is a settings page to choose from a list of quicktags you would like to use.
Currently on the list of options are: p, br, h1, h2, h3, h4, h5, h6, pb
This plugin was written by Shawn Hayes at <a href="http://sharewebdesign.com/" rel="nofollow ugc">Share Web Design</a> to make it easier to implement useful quicktag buttons. If you have any questions please feel free to visit our contact page at <a href="http://sharewebdesign.com/contact-us" rel="nofollow ugc">Contact Us</a> or post a question in the support area at <a href="https://wordpress.org/support/plugin/simple-quick-tags" rel="ugc">WordPress.org</a>.

Simple Quick Tags

Simple Quick Tags allows you to add useful quicktag buttons to the Text (HTML) mode of the WordPress WYSIWYG editor via a settings page.

David’s Ultra Quicktags vs Simple Quick Tags