Are you clear on the following facts? There are many differences between pages and posts. There is only one dynamic page in a blog for posts and we cannot post to more than that one page. But we can create the appearance that we have posted to more than one page. We organize posts by assigning categories to them. You can create a custom menu and add the categories pages which are automatically generated when you publish a post 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/
If you do not want all the posts to show on the main page, then you can create a static front page for your site. If you wish, you can also create a “blog” page, but you do not have to if you do not want to.
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 Choice 1 static front page then you have to create two pages. One for the static front page which you can call anything you choose example “Welcome”, and one for the blog posts to appear on which you can call anything you choose example “Blog”. Adter your do that you go here . Settings > Reading and make the designation change and click “save changes”. http://en.support.wordpress.com/pages/front-page/