You also need to do things like select a theme. What will your design look like? Will you use a standard theme that's free or will you splurge on a premium theme? There are literally hundreds of thousands of WordPress themes that can be chosen to hep you with the design and layout of your blog. Two of my favorite options for sourcing premium WordPress themes are Envato's Theme Forest and Template Monster.
Working with advertising networks isn’t your only option when it comes to selling ads. If you end up with enough traffic, advertisers may come directly to you and ask you to place their ad on your site. You can also contact advertisers yourself. The biggest difference from the above mentioned option is that there is no middle man, which means you can set your own ad rates.