Don't feel bad. I recently had to be walked through this whole process by the extremely helpful folks on this board.
The only way you can post a photo is via web-hosting. I believe most Internet Service Providers offer web-hosting as a feature of their service. If your ISP doesn't (mine doesn't), you have to go to a third party service, which entails (correct me if I'm wrong anyone) setting up your own website, if only for the purpose of caching photos. There are several web-hosting services out there, and IMO you get what you pay for. I settled on www.100megs24.com,
which costs me $100 a year for 100 megs of space to fill on my site. Eventually I think I'll fart around with building a website, but for now I'm just using it to warehouse images. But I digress... There will be tools to transfer images from your computer to your site, and once there you access them through their unique address at your site.
After setting up your site, you post images on the b.com bulletin board by clicking on the image button next to the smilies in the "Post A Reply" window. You'll get a field where you type in the complete address (url) of your image at your site. Sorry if this sounds like Computer for Dummies, but that's the only way I
can understand it. I think it's a lot of work up front, but it's worth it to be able to communicate better. Hope it helps.