Adding a Blog Post
First, click the + New tab and select 'Post' you will now see a page editor that looks like this
Give your blog a title and then start with your copy. It works the same as a standard text editor which you can type into directly or copy and paste from another source.
If you are creating lots of blogs relating to different content then it is a good idea to use the categories feature. Below is an example of how it could be used.
If you want to include an image in your blog then click the 'Set featured image' link. The reason for adding the image here instead of the body is that on your blog landing page you can select to have feature image turned on or off.
On the landing page, it will automatically pull in the image you select for the featured image