You have to get the pics hosted on a remote site for public viewing, as people are not allowed access to your hard drive. By personal choice I use the website 'Tiny Pics' which offers free hosting.
Now in 'practice'.
1. Put your scans in 'My Pictures' within 'My Computer' and make sure they're the right file type (eg jpeg) - and - very important - not too large (suggest 300 x 300 max). You can use Photo Edit to achieve that.
2. Go to "Google" and type in tinypics.com (choose the website) which will open a form for you to browse your own computer for the relevant pic. Ignore/gloss over any blurb that says "Congratulations you are our millionth customer etc."
3. Click on your scan/pic so that it gets uploaded into the box (and picture appears on the right).
4. Right click "Copy" and try and exit "tinypics" (be persistent).
5. "Paste" onto wherever you want it to go. It will go in as a URL address, which when you look up the posting entry you made should then appear like magic as a picture.
You can always experiment by using the Private Message system: send yourself a PM with a tinypic in and see if it works !
Hope this helps. Any problems, don't be afraid to come back to me !