As of version 2.73 from 2015:

• Make sure render engine is set to cycles (BI wouldn't create the required cycles materials)
• Select the object you want to emit smoke
• From the menu Object/Quick Effects pick Quick Smoke

After that a material has been created that looks like:

In order to also emit flames it can easily extended:

Important settings for the Domain object (besides higher-resolution):

Important settings for the Flow Object:

Add a procedural texture and animate some properties to animate the flames

Full tutorial: http://www.blenderguru.com/tutorials/make-fire-cycles/

As of version 2.73 from 2015:

• Make sure render engine is set to cycles (BI wouldn't create the required cycles materials)
• Select the object you want to emit smoke
• From the menu Object/Quick Effects pick Quick Smoke

After that a material has been created that looks like:

In order to also emit flames it can easily be extended to:

Note that the attribute names have to be exactly as they are show 'color','density' and 'flame'.

Important settings for the Domain object (besides higher-resolution):

Important settings for the Flow Object:

Add a procedural texture and animate some properties to animate the flames.

Full tutorial: http://www.blenderguru.com/tutorials/make-fire-cycles/