Hi there! I don't have many posts, but I was able to post a picture last week using the url from an online photo hosting site. (I know, though, that there are several things I can't do yet . . . add an avatar, I think, and maybe I can't post a non-hosted image or do a photo signature?) Anyway, I use photobucket.com. All you do when you're typing your post is click on the "Insert image" icon -- the one with the tree. It will bring up a box that tells you to enter the url for your image, and you just enter that info as it shows up on your online photo hosting site.
Welcome, and good luck! Hope to see a photo of your cutie soon!