There is no longer any need to upload your pictures to a separate hosting site and add only the URL although this is still possible.
When you create a post you will see a tab at the bottom of the screen called “Upload Attachment”. If you click on the header then there is a place to browse for you picture on your PC. Once selected you can click “Add the File”. Once the file is uploaded you can add a comment if required and then click “Place Inline”.
You can repeat this to add additional photographs
When you click “Preview” or “Submit” you will see your photograph(s)