After adding your picture from your hard drive do not click Preview Post as this will delete the link to your "File Attachment" picture. Click Add Reply and your picture will show up.
This will only allow you to add one picture per post and it will be hosted from my webserver.
The second way to post pictures is using an Image Host, this allows you to add multiple pictures up to 4 per post. This uses the Image Tag under iB Code Buttons or you can manually enter your info using the [ IMG ] tag.
Try and limit image sizes to less than 800x600 in size
If you need pictures hosted let me know I have plenty of space on my server and will gladly host pictures and post them for you!