For the twentytwelve theme (looks like that's what you are asking about), those are widgets - and if you don't want them on any pages or posts, you can get rid of them by going to Appearance >> Widgets screen and moving all the widgets off the Main Sidebar section (right side of the page) - just drag them to the Inactive Widgets section. This may explain better:
http://codex.wordpress.org/WordPress_Widgets
Then if you only want pages (vs. posts which are more blog-like) just use pages in your site.