As a resume writer, when you think about "writer's block," you probably think about the times you're stumped while writing a resume. But many of the resume writers I talk with say that they find the blank page most daunting when it's time to write something for their blog. The phenomenon is common enough that there's a name for the condition -- "blogger's block" -- the condition of not knowing what to put in your blog.
It's easy enough to amass content on your blog -- creating blog posts that are links to other articles, for example. But your blog should feature your voice. It's fine to look for articles in the media -- watch the news, read the paper, check media websites. Look for articles sourced by resume writing colleagues on Twitter and Facebook. But instead of just linking to the story, comment on it. Link to the original news source, but give your opinion about it.
You can also use your blog to promote affiliate programs you work with. Amazon's affiliate program is a great example of this. All of us read (and probably, collect!) career-related books. Take a few minutes to review the book -- including if you'd recommend it to job searchers. You'll have something to write about, and if your blog readers click on the link and purchases the book, you'll make a few cents (or dollars!) off the purchase too.
Blogs are also a great way to promote your website -- especially when you've posted new articles. Create a blog post that contains the first few lines of the article to tease your readers, as well as a link to the page that features the full text.
Keep your posts timely and helpful. Look for natural tie-ins with holidays and career milestones. (For example, with St. Patrick's Day coming up, now would be a great time to write a blog post about how jobseekers can improve their "luck" in the job search.)
To help your readers stay up to date with the new posts that you add, you can install a feed burner. There are different feed services to choose from, including free ones. Once you register, you will be given a small amount of HTML to add to your blog. Your readers can choose to subscribe and have your new posts delivered to their email automatically. (Find out more about RSS feeds in this blog post.)