Your opinion--should writers blog about writing, or about the other things they do? I've read different opinions, and I'd be interested in yours. :)
Well, who do you want to read your blog? Me? Better not write about writing then, cause frankly, I'm not interested in how many pages you finished today, or your difficulties figuring out how to get that 15th point of view in your 49k manuscript.
I think writing about writing is best done in small doses and infrequently.
If you're writing to build a readership, no one is interested in your process except other writers. You want to reach beyond that group. You want to reach READERS.
Thus, writing about BOOKS is better suited to building a readership.
Of course, Chuck Wendig's blog is an absolute exception to this, but he writes so fiercely that really, I'd probably read anything he wrote including "17 Uses for Kale"
Writing short form blog posts is a really good way to practice writing. I encourage you to do so, but it's all pointless without readers. Plus, it's a whole lot less fun. The readers of this blog crack me up , and I look forward to reading the comments column every day.