Hi Thomas, welcome to ThePhotoForum.
Easiest way is to open up an account with one of the many free photo hosts out there in the www (www.photobucket.com or www.fastpictures.com or www.flickr.com or any of the many, many others), load your photos up there and to link them to here.
You can either use their direct IMG-codes (with the necessary brackets already wrapped around the URL of your picture) or you copy the URL as is and use this forums Insert-Image-Icon (little square with yellow sky and grey mountains and sun above the reply box). Watch out: it does NOT work with pictures stored in Photobucket. You must use the FOURTH line of URLs underneath your pics (IMG-code), nothing else works.
And should you store with flickr, then make sure never to copy the funny v?=0 behind the .jpg-extension of your picture URL. OK?