Here's what makes a "good" blog (of any kind) in my book:

- this is how we did what we did

- this is why you need to think about this thing, and here's a way (or ways) to think about it

- I got really bored, and did this thing - have at, Intarwebs

- here's something that I tried that didn't work, and I wish I knew why, or here is why (at least in this use case)