http://www.avianweb.com/toxicfoods.html

Below is an excerpt from the above mentioned website listing toxic foods, plants and woods for our birds. 

This is not a complete list. It is recommended that you consult with a vet, if in doubt.

Please note that the items marked with an* are especially toxic to birds and can be fatal.Toxic foods are foods that can cause allergies and/or health problems in birds. Anything high in sugar or salt is inappropriate, as are fatty foods. More serious are things such as chocolate, which is toxic to many pets. Caffeinated or alcoholic beverages are also dangerous. I provided additional information as was available.