First join a site which allow photo sharing. For this example i will use photobucket.com
So, first click join and provide the necessary data they ask.
second, log in.
After logging in, upload the picture you want to share. Click "browse" and search where your file is located.
After doing so. click "upload"
Then wait until the uploading is complete and your page refreshes.
After which you are asked to input a tag and description. you can ignore this and just click "save and continue".
The page will refresh and then scroll down. You can find the picture there and then click on the "IMG" code and copy it by pressing "ctrl + c" simultatiously.
Now go to you forum and paste the code in the post.
That's it hope it could you..