There are some directions in the New England forum in the FAQ, but in short form:
Upload photos to a photo hosting site and set options for sharing.
Select the photo you want, set the size (I usually use medium-large) and then copy the embedding code AKA HTML (not the link AKA IMG code) directly into the body of your message. Repeat as many times as desired.

Or alternatively, just put in several responses to the same post, changing the title each time so that the software that runs GW doesn't think that you're mistakenly posting the same thing twice.

Here is a link that might be useful: How to include multiple photos in one post

I on the other hand, can't seem to post single photo I'd like to address in a question.

For multiple Photos, I create an album in Picasa (the hosting site my kids set up for me) I copy the album title & paste it to the Optional Link URL box (rt at the bottom) & add a title to the link.

I hope this helps ~ would love to see your album, bloomorelse!!!

Ditas - If you edit your post after you hit the preview button, you have to reselect your photo as well.