Please be sure you fully understand the differences between Pages and Posts. http://en.support.wordpress.com/post-vs-page/
The front page of the blog by default will display your posts (not pages) in reverse chronological order, with the most recently published post on top. If you do not want all the posts to show on the front page, then you can create a static front page called for example “Welcome” for your site and a “Blog” page for posts.
To do that create two pages > http://en.support.wordpress.com/pages/ After you do that you go to > Settings > Reading and make the designation change and click “save changes”.
Front page displays
__ Your latest posts
A static page (select below)