I you use Evernote, or you're willing to use Evernote, there is a blogging solution that will work automatically from an Evernote notebook. I've been playing with this for about a week now, and rather like it.
Pistach.io is associated with a notebook in your Evernote account. You make or move a note to that notebook, tag it as "published" and it automatically gets added as a new post note in your Postach.io blog. Pretty much all the formatting you do in the Evernote app, or on the Evernote site is shown in the blog post, not always exactly, but usually pleasing. There are several simple themes to choose from, and you can personalize them with header photos (if supported by the theme) and an avatar. It's possible to do more if you want to dive into the CSS, but it's not necessary for a simple blog.
Comments can be added by associating your blog with a Disqus account. Again, not necessary.
The account can be associated with your FaceBook and Twitter accounts. You can choose to automatically post new blog posts links, or do it manually by adding fb and/or a tweet tag to the post in Evernote.
Basic Evernote, Pistach.io, and Disqus accounts are all free; though both Evernote and Pistach.io offer extra features for a $5 a month subscription (cheaper by the year). You can check them out, and experiment for free; then pay if you find there is something more you need, or if you just feel like supporting a great product (my primary reason for subscribing).
Another possibility, if you it's just a one-off blog that you don't care about maintaining for the indefinite future, is HTML Egg. You can create and update a simple website/blog completely from the iPad. I think Pistach.io and Evernote make a better, easier, more flexible combination, but I'm probably biased because I'm already a heavy Evernote user.
