Basically, figure out the theme of your blog and what kind of people it attracts and then find affiliate programs for that.
For example. Let's say your tutorials are for developers. What do developers need?
* development tools * hosting * further courses/learning
That will yield a pretty good list of affiliates that will convert well such as:
* New Relic * Digital Ocean * TeamTreeHouse
(respectively). You'll make much more cash, and it'll work better for your site. [Checkout my site](http://antjanus.com/) for instance. I have a TeamTreeHouse ad (affiliate) which makes me a solid $X every month. The adsense ad underneath makes about $X/100 (it was slightly better when it was at the top of the sidebar but still made only a fraction of what the TTH ad made). I also have an ad for Bootstrap themes on my Bootstrap tutorials. That ad makes about $X/2 BUT my teamtreehouse ad performed at $X/25 for those articles, makes sense?
Anyways, I'm getting rid of adsense in favor of my own "ad network".
EDIT A good example of other people doing this is [TechPro](http://tech.pro) (I worked there briefly during the first sprint to make a pre-alpha whatever) which has its own ad serving network and directly serves affiliate programs.