Agree with Todd's general setup. CPM's on display ads are in a death spiral thanks to a glut of inventory and programmatic buying/targeting options.
Particularly for a tutorial site I would consider paid, clearly marked sponsored tutorials that you produce and keep full editorial control over. In moderation it can work well and still have educational value for readers and drive results for advertisers way beyond any display ads, and significantly more revenue for you.
Full disclosure I handle direct ad sales for publishers with this exact same model at TechCrowds.com (including representing a few BuySellAds publishers)
Particularly for a tutorial site I would consider paid, clearly marked sponsored tutorials that you produce and keep full editorial control over. In moderation it can work well and still have educational value for readers and drive results for advertisers way beyond any display ads, and significantly more revenue for you. Full disclosure I handle direct ad sales for publishers with this exact same model at TechCrowds.com (including representing a few BuySellAds publishers)