make an account with photobucket.com, or imageshack.com. Upload the pics u want to their site so u can host the pics on the internet. After you have uploaded the pics you will have an album that u can go to that looks something like this.
You must be registered for see images attach
then as u drag your mouse over the pics this menu pulls up and u click on the bottom link that says IMG code like so and it copys it, then paste that link into your message your typing on the forum and that image will appear on here.
You must be registered for see images attach
Kinda hard to explain try it out and let me know if that makes sense
-Jordan-