Pages are static and are for content that rarely changes. They sit outside of the blog structure and you cannot post to multiple pages in any blog. There is only one main page for posts in a blog and all posts will display on the main blog page. There is no way to exclude posts from the main posts (blog) 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 "Welcome" for your site and a “Blog” page for posts.
Choice 1 static front page
Choice 2 running page for all posts on front page
Which do you choose? It’s one or the other.
If you choose a static front page then you have to create two pages as I said above. After you do that you go to > Settings > Reading and make the designation change and click “save changes”.
Though there is only one dynamic page in a blog for posts and we cannot post to more than that one page, we can create the appearance that we have posted to more than one page. We organize posts by assigning categories to them. You can either put the categories widget into the sidebar, or you can create a custom menu and add the categories into the custom menu.
Here’s a link to a custom menu walkthrough > http://onecoolsitebloggingtips.com/2011/08/11/wordpress-com-custom-menu-walk-through/
There are many common errors, misunderstanding and misconceptions when creating custom menus and you can read about them here > http://wpbtips.wordpress.com/2011/12/19/custom-menus/
On the bottom of your Admin page you will find a link to the Learn WordPress.com blogging Tutorial prepared by Staff. http://learn.wordpress.com/
The support documentation is all found at the Support link http://en.support.wordpress.com which is also on the bottom of your Admin page. The searchbox there provides results from both the docs and from forum threads.