You Wouldn't Write a Book Report without Reading the Book, Right?
Of course, in my day, there were many high school students that just read the cliff notes to do a book report. I am sure that today, kids just browse the web and cut and paste a report together. Either way, it's a shortcut that most teachers will quickly detect.
Readers of your blog, or the lack of readers of your blog, will know when you don't read other blogs too.
You shouldn't write a blog unless you read other blogs. Reading, commenting and linking to other blogs are more important parts of growing your blog readership than writing great content is.
Get yourself an account at Google Reader and start subscribing to some blogs. Read them for inspiration. If you're human and you know how to relate to people, leaving comments and linking to other blogs will happen naturally. Guess what will happen next? People will start reading your blog, linking to you and leaving comments. Then, you'll have a successful blog. Kinda like getting good grades helps you succeed too.