How to start a project to build a quad bike?

Has your friend checked out YouTube? Nowadays just about every learning experience is there on YouTube videos. He will obviously need to know and source the right engine first around which to build the quad bike. Then consider the wheels, right height and steering. I would suggest too posting a query on how to build a quad bike from scratch at off road community forums, such as the one of the popular portal www.team-bhp.com. Your friend might get not just expert tips but maybe a mentor too.

I would also like to suggest having a look at the various types of quad bikes offered by Polaris India (http://www.polarisind.in/), where your friend can see the specifications of the bikes to get an idea of what all is required to build his own. Perhaps be could even get in touch with their dealers in his area (see dealer locator section) to find out if he can get a bargain on their spare parts to use for his own quad bike.

All the best to your friend for his entrepreneur spirit to building his own quad bike!

You can go on Youtube and there you will find lots of videos about quad bike and how to make it. But let me tell you one thing, that if you are willing to make it special then utilize your own mind and believe in your own ideas. If you succeed then you will feel proud than seeing on Youtube and making it. But if you are in hurry or lack information about these things then maybe Youtube will be the best option for you.
Good luck and do give me a ride when you will complete it.