I'd tell you but then I'd have to kill you.
I'll give you how I do it, how you do it is up to you.
http://www.villagephotos.com/members/
I use village photos, it's free. Down load or log on or whatever you have to do to get it on your computer.
Take your picure of your "thing" and load it somewhere on your computer, like "my pictures" or in a picture editing program, whatever you're using now.
On Village Photos, go to "upload photo" and it will ask for the directory of where you have your photo. It has a browse area and I click on that and then go to my photo in "my pictures" and double click on it. It will upload it to your village photo file (I have one I call eBay just for posting photos on the boards)
After it is uploaded, it will ask you if you want to continue. Click on that and it will bring up the photo. Under the photo will be two boxes with file directories in them, one in each. The bottom of the two is the URL file. Click on the file inside the bottom box and it will highlight the whole file. Go to your menu bar at the top of you screen and hit Edit, Copy or right click on the file and hit Copy. Make sure you got it all, the brackets, URL stuff, etc.
Then come to the boards, enter that you want to post a reply and then the Post a reply box come up and it is blank, enter the cursor into the empty box and right click and hit Paste or hit paste from the edit menu at the top of your screen. It should bring it all in as a file directory. You will not see the photo until you hit preview or submit.
You can add normal text before or after the photo in your post.
Sorry I don't know enough about computers to tell you how to size it, etc. And, village photos won't let you upload a photo if it is too big and takes up to much "space".
Try it, we'll understand if you mess up the first time or two.
Good luck.