This is easier to do than explain. 3 ways:
*****The wrong way:
Hotlink from a site that doesn't allow hotlinking, so all people see is a little blue box with a question mark. Note you will see the image, because it will be in your cache. If you don't know if it will show, while you are in the reply window, clear your cache and poke the button to preview your post.
Pictures of children and transexuals are verboten.
Hotlinking is OK if it is OK from the hosting site, but realize it might go away. Linking to you own site or file sharing bucket is the same deal.
Images on the forum are restrained in pixel size, so make it under about 200 or so kb, I suggest. Makes 'em load quicker.
*****The right way:
Save the picture and upload the file to this server and display it. From the reply window, click on the "File Manager" link. It will open a tab with file handling tools. Click the "Choose File" button and a file dialog box will open on your machine. Choose the file you want to display. You will see the file name beside the "Choose File" button. Click the other button that says "Add File". There may be a momentary pause while the file uploads. After it does, you will see the file name up above the larger caption box, next to a 5 digit number. If you are only adding one file, click the "Done Adding Files" button.
Back on the reply window, you should see the number of files (max 5) you uploaded next to the "File Manager" link. You must enter something in the reply textbox. Click the "Submit" button. You will be returned to the forum with your post.
Now, you will see the attachment(s) at the end of your post. Open it (I like to right click and open in another tab) and copy the URL of the attachment. Click "Edit" to edit your post. Above the text box for the body of your post (in the edit window), you will find the icon for adding pictures.
It will ask about non-floating, etc. choose any one. A dialog box will appear, paste the copied image URL into it. The image code will appear in the text box. Click the button to allow you to preview the changes if you wish, you should see the image below. Click out of the editor and you are done.
*****My way
Upload the image files as described above. The code will be:
Note the above is an image, and the number is the 5 digit number from the File Manager, and I know the filename. I enter the code in advance, all I have to do is type in the number. So for the above I retrieved the number 43429 and inserted the filename "example.jpg"
-Chuck