This topic should probably be moved to the Tips & Techniques subforum as it's not really specific to Nikon.
When doing an image tag with BBcode, you need to link directly to the image file - a link to the gallery or image placeholder won't work when placed in the tag. I've taken the liberty to do it for you.
Gordon did a video tutorial for this exact effect. Why not take a look?
http://www.dslrtips.com/workshops/How_t ... hoto.shtml