Welcome Jack,
Regarding pictures, first set up a photobucket account
http://www.photobucket.com and uploaded your pictures, click in the IMG code box under the picture and photobucket automatically copies the code to your clipboard. The auto-copy is one of their recent upgrades.
Now go to your forum post. Right click and choose Paste or press Ctrl and V on your keyboard. That will paste the text from your computers clipboard into your post...
Use Preview to check you got it right before posting
Hope this helps