It really is quite simple. Don't make them too large. Save them on your computer where you can easily go to them- such as in your pictures folder. In your post, use the advanced editor. Click the manage attachments button and it will bring up a dialog box. Find your picture using that and tell it to upload. Once done uploading it, click post or if edititng, save. It should work, but if not it may tell you it was the wrong file type or too large.