Below I have already added my posts to my pages. It is quite simple. I have created a menu where the pages are the top menu. From here follow these steps

1 - Click the box beside the post you want to put under the menu (a check mark will show up in the box for all the posts you select.

2 - the click on the Add to Menu buttom at the bottom of the posts list.

3 - the posts will now show up in the Menu Structure section at the bottom.

4 - now click on and drag the posts under the page you would like them to be seen. (note that the posts you want under the pages need to be indented a bit.

5 - Once you have completed this simple click on the save menu button located at the top right hand corner and you are done.

here is what it will look like with these menus...........