To Build a Good Blog, Consider : Usability

Steve Krug wrote a book called Don't Make Me Think and that's exactly what you should be aiming for when visitors comes to your blog. If they are looking to read your content they should be able to find it and read it with ease. If they want to subscribe to your blog, they should be able to find your RSS feed with ease. Whatever it might be, you want to make it as easy for your readers as possible.

Here are a couple things to keep in mind.

Your website's content should be easy to read as well as easy to navigate.
Make it easy for people to find your content by using categories and by having a search feature on your blog.
Make your RSS subscription button easy to access for anyone looking to read your content from a RSS reader.
Limit the options and features on your blog. Why have tons of features when 90 percent of your visitors only use a handful of them.
Try to avoid technical jargon when possible and when you cannot try to explain the jargon in as few words as possible.

source:
http://www.pronetadvertising.com/articles/5-ways-to-building-a-better-blog.html