WordPress Plugin Repository has a new Twitter Bootstrap plugin which activates various Bootstrap shortcodes you can use inside your content with the help of its TinyMCE button for visual insertion of shortcodes.
So first of all install and activate the new WordPress plugin Shortcode For Bootstrap. After activation the plugin adds its TinyMCE button in your WordPress visual editor present in your add new/edit post pages.
Simply click the button and select what bootstrap element (using its dropdown) your like to insert inside your content and finally click Save Changes button.