Same questions here too!
I'm on Jive-x, too but the community is exclusive to customers and our employees, so really our only way of promoting these blogs is by sending them out via our Slack channels or email. One thing I like to do is comment on posts that are similar/relevant with the link to the blog post and provide some context so that it doesn't come off as spammy.
To give some additional background.
My community is an external peer to peer that my customers use to share best practices and problem solve.
Our blogs are written by engineers with the goal to share additional tips and ways to optimize your use; they are technical, not marketing or promotion.
Thank you for your suggestions.
Tony, would you share a link to your site, if it's visible to the public? I'd like to get some ideas for a new site by seeing how you are using a blog for this purpose.