I fooled around with this for about 30 minutes this morning and finally figured it out. Here's the best way to post a large image in your post (not a thumbnail that someone else has to click to enlarge)
1) Upload image to photobucket
2) Right-click on image and select 'copy image location'
3) Within the 'reply to thread' message box type:
[img]
4) Paste link right after [img] - make sure there is no space
5) Then type [/img] right after the link location that you posted (no space here either)
6) Submit reply
Your picture will be up!!!!
Here's an example:
