I had no idea how to post a picture or image on a post.

After some reading on the forum, I following the suggestion
of using "rimg" tab.
The "rimg" tab is above to the far right; then go to your picture file
and drag the object onto the white posting box. If successful, the
border of the posting box will have dashes on all four borders.
On the bottom of the post there will be a box which allows for
varies options, including image deletion. You can also review your
work by pressing the "preview" tab.
This also works with images of your OS, such as the "Disks" file.
I use "Screenshot" as my choice for recording pictures and images
off the desktop.
The picture of "Sire Hunter" came from the download file.
Since I am a relative newbee to Linux, I welcome additional comments,
as I am sure there is more information which I did not address.
What the file capacity is I do not know, however, 300 Kb image would not
post; which was a screen capture of a page on my 19" monitor.