1.how to start off.

Speaking specifically to the CEH, you might want to start out by taking their prep class (http://www.eccouncil.org/education.htm), particularly as this will be a requirement to sit for the test if you don't already have 2 years of experience in the field.

2.is there good demand of ppl with the CEH certification and no exp.

No experience might be a bit of a toughie. My suggestion would be to hook up with one of the professional organisations for security folks, such as the ISSA (issa.org) and start keeping an eye out for an internship.

3.ho  w much time will it take me to be certified if i start from scratch and give aprox. 10 hours a week.

If you're starting from zero experience with the concepts and tools, it might take you a while at that rate. The class will be a good starting place.