In our project on google map, we have to display some custom marker pins use png.

google api provide great function for this purposes.
Here is a example URL
https://chart.googleapis.com/chart?chst=d_map_spin&chld=0.3|0|78909A|13|b|
you could change scale 0.3 to any size with fill in color 78909A,
font size 13 is for font to put into pin text

click on the url to view excellent markers.