Raise the topic of writing a book and most people will look at you aghast. The very idea of writing a book conjures visions of a gargantuan task, the literary equivalent of climbing Mt Everest (albeit without the need for supplementary oxygen). You may even be thinking along the same lines. Writers write books, and I'm not a writer.
A blog, on the other hand? No big deal. Tell people you're writing a blog and some will be impressed while others will secretly be wondering if you'll manage to get out more than three posts.
Nevertheless, a blog seems more manageable than a book. A post once a fortnight, say. About 600 words. You don't need to be a writer to do that – just capable of writing a few coherent sentences.