There's a "new to gardenweb" thread that floats around the Kitchens forum - posting involves creating a photobucket account or similar. I found it wasn't too hard from there.

Here is a link that might be useful: posting pictures

Here's a simple explanation

To add photos:

<img src="Your URL location here" </img>

For instance, say I wanted to show you a photo of this sink I saw on Faucets Direct

The place I found the photo was

http://www.faucetdirect.com/kraus-khu100-32-kpf1622-ksd30-32-undermount-single-bowl-16-gauge-stainless-steel-kitchen-sink-with-kpf-1622-kitchen-faucet-and/p1755769

but there was a lot of other stuff on that page I didn't want to show you. So I tapped two fingers on my touchpad while the cursor was on the photo and got a list of things including "copy image location." That gave me

http://www.faucetdirect.com/imagebase/resized/330x320/krausimages/kraus_khu100_32_kpf1622_ksd30ch_0.jpg

and that's what I pasted into the URL spot. Non-Mac computers may handle this differently, but there is a way to do it.

If your photo is coming from Flicker or Photobucket or the like, they have directions on how to copy the image location from there.