Writing good content for a blog, whether corporate, personal, or otherwise can be incredibly challenging.
Creating content and presenting it in a thoughtful and engaging manner, consistently, is a skill that can take some years to build up. And you never really get there - it's a continuous practice that you can always improve on.
However. Measuring and tracking the success of your blog analytically isn't nearly as difficult. In fact if you are tracking the proper items surrounding your blog you will be able to gauge your success and momentum allowing you to alter your strategy if need be or push harder the direction you're going.
The analytics you choose to pay attention to surrounding your blog will be largely driven by the goals you have in place for this piece of your website. If you haven't defined your goals yet - I'd suggest starting there.
That said you can derive valuable information from most all of them about how your content is received, what effect it is having on the traffic to your site, etc even if it isn't directly tied to a KPI you have set.
Given that - I would encourage you to create a holistic dashboard using as many metrics as make sense for your business. From here you can build out your regular reporting if necessary. You'll need to be sure and frame the measurement of all of the metrics you are pulling with the amount and regularity of content you are creating. Everything else, or most everything else will be in direct relation to this so it HAS to be considered. Beyond that here are some more suggestions to look at.
Visits and Visitors
This is a fairly broad metric but can give you a very good idea if your content is reaching anyone and if they're reading it.
An important note here is that visits and visitors are different. For example, one "visitor" can have multiple "visits" to your blog. It is important to understand the definition of this metric in your particular tool set as I've seen several that refer to them in unique terms.
Keeping in mind that your actual blog is not the only place readers can consume your content of course. More on that in a few bullets.
Engagement
Measuring engagement can be kind of tricky on a blog. Depending of course how you define it.
I measure engagement separately from sharing while I know others who lump them all in to one category. For my purposes I measure engagement by the number of comments and 'Likes' on each post. I use a separate 'Share' button for Facebook which is why I personally like to include the 'Like' in engagement. It's a vote or a 'Hey - I liked this' so it goes in the engagement category.
There is no prime ratio for this. It's a way of measuring yourself, against - well, yourself. Not every post will warrant comments. Nor should you expect it. There's also no "ideal" number of comments. This is simply a way of encouraging yourself to create increasingly engaging content and being able to track your progress. It can also give you a really good idea of whether or not your readers are enjoying the content you're publishing.
Sharing
Closely tied to engagement is that of sharing. A reader doesn't have to be engaged to share and they don't have to share (as used here) to be engaged. But quite often they are very closely related.
Sharing analytics are just what they sound like. And depending on what tool you're using for this you'll have different availability of metrics. ShareThis for example provides some pretty decent metrics available. (Take a look at the availability of the tool you're looking at before implementing. It's very difficult if not impossible to gather this data retroactively.)
Are users sharing your content via email, IM, Twitter, Facebook, StumbleUpon, Digg, Reddit, (and on and on)? If you find your readers are very actively engaged on your blog but not sharing as often as you would like consider taking a look at on-page optimization possibilities. Take a look at your blog and make sure your sharing buttons are easy to find and use. Beyond that try different placements to see if that changes up the results. For example, perhaps moving them from the top to the bottom will have a positive benefit in this way.
RSS Subscribers
Don't forget that on your actual blog is not the only place your readers may be consuming your content. Be sure to track and measure how your users are interacting with your content through RSS by using something like Feedburner or whatever your site will allow.
As I mentioned previously this is tied in quite closely with Visits/Visitors. I put it here however, because if your numbers are not what you would like them to be you can try optimization efforts similar to those you might use in optimizing for sharing. Users generally subscribe to your RSS via a RSS button so you'll need to test on what gets the highest conversion among your visitors.
Path Analysis
Sure your readers can find your content on social sites or via RSS. But can they find you from other pages on your website?
Check out your path analysis to find out. How are they getting to your blog posts from within your site? And once they get there you'll also want to look at where they're going. What is their exit path?
If they're hitting your blog and leaving then maybe you're not doing a good enough job "merchandising" your blog content. Consider highlighting top posts, or moving the category listing etc. Looking at the path analysis can also help you to determine what people are looking for. Use that insight to make it easier for them to find that information.
Bounce Rate
There are a lot of intricacies around bounce rate. It's quite often used in promotions to measure their success.
Keep in mind that many things can influence bounce rate. For example if someone is entering your site on a particular search query that they quickly find the answer to they'll likely exit soon thereafter. If they're entering from a social sharing site like StumbleUpon or Reddit the bounce rate would likely be different. But that is generally quite individualized.
It is an important thing to look at in judging, on a blog specifically, how long people are spending ingesting your content and whether or not they're looking for more once they arrive.
Inbound Links
While not necessarily a measurement of success (depending on who of course, you're talking to) it can be quite interesting and valuable to take a look at what conversations you are inspiring elsewhere on the web.
If someone is blogging about you, chances are likely they will link to your post that incited the conversation. Of course if link building is one of your goals for the blog (which would make very good sense) then this will be an even more important metric. You may approach your content slightly different at times as well because of it.
Is there more?
There are many other specific metrics to look at in relation to your blog than I've listed here.
To find out what you should be measuring it's imperative to ask yourself "What story are we trying to tell here?".
You need to know what questions you want to answer first, or what story you're looking for. Then you can dig into the analytics and pick out the ones that help you answer these questions.
What is available to you in terms of data will be largely determined (and possibly constrained) by the analytics you're using on your site but most should cover the basics for sure. Look around for other tools that you can tack on if need be. Chances are likely that you're spending a great deal of time managing your blog and if you are unable to present your work with numbers and data within your company it will be as if it never happened.
"In God We Trust, All Others Bring Data." -- W. Edwards Deming