Don't sacrifice morals for a quick buck — At the outset, you'll want to do all sorts of things to make money online, but don't sacrifice your morals for a quick buck. Not only will you put people off, but you'll lose Google's trust. You also shouldn't concern yourself with things like Adsense or other ads on a blog before you have around 100,000 visitors per day. Yes, per day.
There are many ways in which you can make money with WordPress. Creating a website for the purposes of promoting a business or selling goods through an online store is one such way. Monetizing a blog with display ads is another. While there are other ways in which you can use your WordPress site to make money, perhaps one of the easiest ones to get started with is affiliate marketing.