Quick hosting/image posting guide:

The photo (if in jpg or gif format, can be attached to your post directly by clicking the host image button . Just use the interface to upload your image, then copy the url (bottom of the three options) then click the image embed button and paste it into your post.

Alternatively, you can upload your image to another source, eg (photobucket) and then attach it to your post by clicking the image button and pasting the url.