if you add [[myimage.png]], org mode will use the file myimage.png as an inline image for myimage.png. You can then run M-x org-display-inline-images to display your inline image.
adding
(setq org-startup-with-inline-images t)
to your .emacs will make image inlined on opening a org buffer. M-x
org-redisplay-inline-images will refresh inlined image if needed.
You could also add
#+STARTUP: inlineimages
to an org file for inlining images only in this file.
