Believe it or not, the FIRST question to answer in deciding whether to do a blog is:

Am I going to have fun doing this?

There’s a very simple reason for that. If it isn’t fun, you aren’t going to do that. We seen this clearly over the years. It is just one of those things. It doesn’t matter how good an idea it is, it just isn’t going to happen otherwise.

Part of that is making sure it is easy to do. And that means don’t start out with overly ambitious goals.
You want to get into the habit of regular blogging, the emphasis being on regular – not on any certain frequency. Whether you do one post a week, a day, or multiple postings over the course of the day, don’t try and force it, but start out easy so you keep doing it.
You can always work up into more frequent and more sophisticated posts (with attachments, pictures, links, etc.) as you get more into it.