I know how irritating it is when you post a question in some software you've chosen, and people respond with "bad choice, bro" but I'm going to do it anyway.
I'd like to encourage you deeply to seek other options for your blog. iWeb is not a scalable solution, and should you ever decide to move your blog anywhere else, well... you can't, not really.
If you use Wordpress or something (and there are some GREAT Wordpress themes out there), you can post from your comp, from your iPhone, and you know that down the line you have options in terms of exporting to other legitimate blog environments.
Trust me. If you make anything of your website, you'll end up redoing everything you're doing in iWeb in a real solution at some point, and it will be a real pain. If you really can't bring yourself to use something other than a desktop app, at least try Rapidweaver. It's like iWeb only much, much better.