There are several methods for cleaning curly hair.  These range from what's called water washing to full-poo. 

Water washing - This is usually done in the shower, with the water running over the scalp and hair.  Using only the mechanical action of the finger tips against the scalp, a gentle massage is done to each portion of the scalp to loosen and release any dirt or dead skin. 

No-poo - Done much the same way as water washing but with conditioner.  No conventional shampoo is used.  You can find a description of a no-poo routine here.

Co-poo - Done with a mixture of conditioner (the co part) and low-poo (the poo part). Start with trying a 50/50 mix of low-poo and conditioner.  You can adjust from there.  A small plastic container in the shower is sufficient to mix enough for each washing.

Low-poo - A non-sulfate based shampoo or soap is used to clean the hair and scalp. In many cases, shampoo bars are preferable to liquid shampoos. 

Full-poo - A sulfate based shampoo is used to shampoo the hair and scalp.  Usually only used by new curlies to remove build up of silicone based styling products or to strip hair color.  Very few curlies are successful in caring for hair while still using sulfate based shampoos.