1.) Find the Right Niche & Advertisers for Your Blog
Before setting up any advertisers, you will want to make sure they are relevant to your blog audience. This is important for two reasons. The first reason is that you don't want people visiting your blog and seeing ads they have no interests in and it just ads to the blog. The second reason is that people take more action when they have an interest in something. If you have a blog about product reviews, then try to find advertisers based on those same products.
2.) Direct Advertisers or Affiliate Programs
Let's look at two different methods for making money through a blog. You can find advertisers directly and they will pay a specific amount per month to be placed on your blog. This sounds great, but it's actually a very hard process to do. The best alternative is to find an affiliate program and link to specific items and services. Every time a visitor from your site clicks on one of your affiliate links and takes a specific action or buys a product, you would earn a commission on that sale. A good example of this is Amazon.com's associate program.
There are many ways to make money with blogging. Be sure to keep adding content to your blog and build up your readership, as that is what's most important.