Oh yeah, you forget a lot of points!
It is not easy to earn money with a blog, it is like you are a newbie and have to learn a lot of things!
I wish it were that simple … lol
There are so many way to get income from internet. According to your listing point above, write Unique quality content is very difficult part … how to create a blog with unique content?
I would say the answer depends on you. Do you enjoy writing? Are you disciplined enough to sit down and write daily on your blog? Remember, you can’t make money if you don’t blog. If you answered yes to these questions this may be a way for you to earn money while doing something you truly enjoy.
You right LindaSimon, first we have to invest our time to write and post unique contents for our blog.
Just thought the 3 steps is good enough for a newbie.
somehow she will learn how to optimize her blog along the way.
You have missed an important point “the King” which is quality content. To get good traffic and for sustained result you need good content. 
What about after creating a blog, you post a content and add adsense to it then posting more content and promoting it? Is that okay?
Adsense is by far not the easiest way to make money from a blog. The thing I dont like about adsense is that you lose your reader or visitor, they click away from your site