How does one add a logo design on a PCB in eagle. I can do is add type, is there a way to add a simple logo?
Have a go at running the import-bmp.ulp. 
import_bmp is what you want.
Suggestions:
Use an image tool to make a bitmap 1 color (really 2 color) image. You will need to hand tweak your image if there are lots of complex shapes - these will get lost in silk.
import_bmp is backwards with 1 bit BMPs - white is black and black is white when picking colors.