I typically don't use the forum upload for images--but here's a link to information on how to do it:
Cruiser Log World Cruising & Sailing Forums - FAQ: Reading and Posting Messages
With the above instructions you should be able to upload a pic to a post.
I just link to pics hosted elsewhere, I have a pro account on Flickr and I also have some pics on my website. You can get a free account someplace like Flickr.com (owned by Yahoo) or there are others devoted to picture hosting just like Flickr. Upload your pic to that site (or the others) and then you can post a link here to the web address (that's the http...blah blah... part) of the photo
um...umsing the little "picture" icon that has the mountain on it! If you right click on an image you'll see something that says "copy image address" and that's your http address bit that you can then paste anywhere you'd like.
I hope this information is helpful.