Question: I tried following a tutorial but didn't get anywhere with it. I wrote a question about it but no one answered here (100 bounty):

[Why am I not getting a grey background in this program](https://stackoverflow.com/questions/4161708/why-am-i-not-getting-a-grey-background-in-this-program)

Since I can't make any progress with that tutorial until someone answers that question, can anyone recommend something else for learning OpenGL? I want to learn how to display rotating 3D objects.

Answer: 
Jeff Lamarche's [OpenGL ES From the Ground Up](http://iphonedevelopment.blogspot.com/2009/05/opengl-es-from-ground-up-table-of.html) series is great for OpenGL ES 1.1 (I also highly recommend subscribing to his blog's RSS feed).

For a nice easy start, there's also a short series of tutorials on the iPhoneSDK blog, starting [here](http://iphonesdkdev.blogspot.com/2009/04/opengl-es-for-iphone-simple-tutorial.html).

If you want a crack at OpenGL ES 2.0, you could have a look at some chapters of Lamarche's abandoned book project, which he's [generously making available.](http://iphonedevelopment.blogspot.com/search/label/Book%20project)

When you want to move on from all this, the Nehe tutorials as jasper mentioned are worth a look. Jeff Lamarche has ported these to the iphone (see first link above).
The tutorials on [nehe.gamedev.net](http://nehe.gamedev.net/) for openGL are excellent. While there may not be anything specific to glES, the core concepts are the same, and should cover everything you need to know.