The easiest way is to upload your photos to photobucket and if you are meerly going to post them, then just upload and let photobucket resize them. Copy the direct link once uploaded and click on the photo icon above in the far left corner (yellow background mountainscape with small square). Paste your direct link into the space provided and click okay. It should then put your photo directly into the post. Sometimes you have to use the arrow keys in the post window to help load the photo completely in. The click OK and you should be done. I see you've already mastered how to upload a thumbnail. Hope this helps.