If you have a photobucket account then it is very easy, just hover your mouse over the photo you want to post (this will open a cascading menu that has 4 options, you'll want the bottom one) then drag your mouse down to the "IMG Code" and right click on the text inside that box, that will place it on your clipboard. then just paste it into the body of your message, like this:
IMG http:/ /i173.photobucket.com/albums/w55/bb021099/photobucket-9552-1316445759748.jpg IMG
I removed the brackets around the IMG so you could see the actual text string that needs to be pasted !! and after I added the brackets back the pic shows below !!

also be sure there are spaces before and after the text you paste or it will show up as a red "X" in other words if you hit the space bar before and after you post a pic you'll be fine !!