If you want them inline, you will need to host the pictures online somewhere. Then when writing your post, click on the first button of the second row of the post editor (it has a very small version of the Mona Lisa as its icon). Clicking on it will give you these tags, but with square brackets instead of parenthesis: (img) (/img) Paste the url between them and it will link to your image.
If you want them simply attached at the bottom of your message, use the attachment option below the text box in the post editor.
