To add a new page:

1. Make sure you are logged in to your site (and that you aren't in the middle of editing a page).
2. Decide which content type is appropriate.  If you are not sure, read more about content types.  Typically it's rare to create a new Basic page, but common to create a new Blog post.
3. Go to your Editing Menu, and click 'Add Content'.  Select the type of page to create - for example 'Blog post'. 
4. You will be taken to an editing form which is entirely blank. 
5. In the 'Title' field, enter a brief but interesting title for your page.
6. Place your cursor inside the 'Body' text box and add your page text.
7. You can format your text in exactly the same way as editing a page.
8. When you are finished, place your cursor outside the 'Body' box and scroll down to see further options.
9. Upload any images that you want (optional - see Add an Image for more information).
10. Scroll to the bottom of the screen and click 'Save'.

For a new Blog post, and most other content types, the new page is automatically linked in to the site wherever is needed.  If you created a new Basic page, then you normally would need to add it to the menu.