This is something that every newbie asks himself.
Basically it isn't if you know what you are doing, but if you start in a wrong way, you sure are not going to make much money.
So you need to know the basics first so you can build good foundation for future.
Main thing in starting online business is planing and first thing you need to plan is around what topic you will create your website.
To choose your niche you need to know what is profitable with low competition in search engines. This is key point for future website if you don't do this right all your efforts will be futile.
After you have decided about your niche you should build a website with some original and quality content. You can use wordpress blogs they are really easy to install, manage and use. Google loves WP too, just use some custom template if you can it will help for your rankings.
I believe that free traffic is the best one you can get(am I clever or what ), so you need to have your website to be on google top 10 results for your main keywords.
For first page on G, you need some quality backlinks, so your next step is to build quality and your niche related backlinks, as more backlinks you build your website will clibme in SERP's for sure.
Now all you have to do is to monetize that "free" traffic .
Yeah I know it sounds to easy, but it can be easy to build successful website if you know what you are doing, or very easy if you can outsource all that work and colect money in the end.