When you are in your Account at Photobucket, Find the Pic you Want to Post & Then Click on img code which is the 4th one down & You will see it turn Yellow for a Moment Say Copied. After Doing that Step you just Paste it into your Post.
This is an Example from my account..........
I would Suggest that you use a Word Processing Program such as Notepad or Word & Type up your Content of what you wish to Post & insert the Image in this by your Text. When Done with all Typing of Mesage & Pasting of Pics in the Document you can Cut & Paste this into the area for your Post..........
I Hope this make's some sence to you...
Rick