Welcome to FSM
First of all, the images you want to post here or use in your signatur, you have to make available on the internet. You can upload them to a site like www.photobucket.com.
When the pic / image is available on the www. you copy the picture URL and insert between
but without the spaces between img and ].
Oh and btw. read this thread http://www.finescale.com/fsm/community/forum/topic.asp?TOPIC_ID=4462
You will find alot of help here.