Zoundry Raven is free, portable, visually appealing and does the drugery for you. It lets you write quickly in WYSIWYG mode and adjust the code gracefully in XHTML mode. Inserting images is super easy. Just copy and paste. Pick the thumbnail size you want and upload. On your blog your thumbnail of course becomes clickable and shows the larger version. Write, categorize, tag, publish - that´s it!