It took a long time to figure this out and I am not very good at this. However if you want to know how to post a large picture at the bottom of your post instead of posting a smaller clip which folks need to click and enlarge -well, this is how I did it and what I suggest.
Go to
Image hosting, free photo sharing & video sharing at Photobucket and download the pictures at the size of 640x480 which photobucket calls "large." After the picture downloads, you will find below that picture four different titles. Highlight the title called image and then paste it (Control,V) in the post. Do not attempt to use the paperclip or any of the image or other clicks included at the top of the post (at least I could not get them to work). At first you only see a name string copied to the post. However, when you hit send, and then look at the post, the picture magically appears. I end up editing many of my posts because the pictures do not work the proper way, but this seems to work.
If you want the picture to appear slightly smaller at the bottom of your post, just redownload the original at photobucket using one size smaller.
Hope this helps.