Here are some 'general' steps
To insert an image into a forum message, you have to 'host' the image on an Internet server. So you first download the picture from your camera, resize the picture with a picture editing software, I use Adobe Photoshop, there are many free ones, then you upload the picture to an Internet server. There are some free picture hosting services, photobucket.com, imageshack.com, etc. you can Google 'free image hosting' and probably find a few.
I host my own domains so this is very easy for me to do this.... I FTP my images to the Internet server, using a program called WS_FTP, some of these free photo services sites have web based interfaces that make it easier than FTPing, you just browse to the image on your PC and press upload. Once the image is uploaded and hosted on an Internet server, you have to know the url, http:// address to the image, you then insert that url into you message by clicking on the yellow button next to the quote button, see below images.
These are the steps after you have the image hosted on an Internet server.
Then this window comes up and you type in the full url to your image.
Then this code is automatically inserted into you forum message, and once you Preview or Submit, you should see the image appear in your message.
After you Submit it should look like this.....
After reading
windthrown's post above, his steps are
much easier, kind of a neat trick linking to the attached photo url.... Very Good Tip.