Here is a resource that explains things.
A lot depends on exactly what you carry. Speaking very generally, if you carry sickle cell trait and your wife carries sickle cell trait, your child will have a 50% chance to carry sickle cell trait, a 25% chance to get sickle cell anemia, and a 25% chance to get neither the trait or the illness. But read the following carefully because that is a general statement only and you need to be more specific.
http://www.sicklecellsociety.org/resources/inheritance-of-sickle-cell-anaemia/