That's a good start. Note that you can attach an image directly to a post rather than having to host the image on a 3rd party site. To do this make sure you are using the advanced editing window for posting (by clicking the reply button, or hitting the Go Advanced button from the quick reply window). Then click the paper-clip icon in the tools above the reply box. This opens up the attachment manager. There you can upload an image from your computer.
When you are back in the message editor, get the cursor to the place where you want to insert the image. Click the paper clip again and you will see the name of your image in a drop down. Click the name of the image you want to insert there and a thumbnail of the image will get included in the text. Any attachments you don't add in this way will be included at the bottom in a separate box.
As for the map, looks good so far. you are right about the bevel on the floor. How are you using the map in a game? Is it for use with a virtual tabletop program?