Average starting salary offers vary by branch of engineering and by degree. For example, in 2006, the highest starting salary offers were in the following specialties: aerospace, agricultural, architectural, bioengineering and biomedical. The amount of the offer increased based on degree level attained.
Median annual earnings for several branches of engineering (U.S., 2006)
Electrical: $75,930
Civil: $68,600
Mechanical: $69,850
Computer Hardware: $88,470
Environmental: $69,940
Nuclear: $90,220
Biomedical: $73,930
source: http://careerplanning.about.com/od/occupations/p/engineer.htm