Nice Blog! I read quite a few entries and really like it. You have successfully presented the case on why most people should hire a professional, but at the same time present good tips.
I prolly can't answer the tags question. Maybe if you log into your blog account and write a blog, there is a button you can click to "add Tags"? When you get to the "add tags" window, I think you're supposed to type in words that relate to your blog post.
For example, on your blog post about "Odd blistering with Grasscloth", you could add the tags: wallpaper, grasscloth, problems with grasscloth, blistering wallpaper, blistering grasscloth, etc.
It helps people find what they're looking for.