I've only been blogging for a little over 4 months and have read a ton of useful and not so useful information about monetizing websites. I am in no way an authority, and can barely understand half the stuff I read. I do, however, love Pepperjam.
Pepperjam's affiliate marketing tools are so easy to understand and use that it was a no brainer when I first, accidentally, came across their site. They have so many advertisers in so many fields, I can pick and choose which ads to place on my site. Ones that are actually relevant to the blog itself or are reflective of things I use.
If your looking to spruce up your blog with relevant ads that you can choose rather than have someone else choose, try Pepperjam. You won't be disappointed and you may even make a little extra money.