what are the best way to research any altcoin before investment, what are the major sites which is very helpful to newbie ??
Best way to research any coin is to get an abundance if information. Only after you have every aspect of information can you make an appropriate decision as whether you want to invest or not. There is no one major site
to help you gather all information, but a really good place to start is in the announcements sections here on bitcointalk. Do not hop into a coin on first glance, make sure you research, research, research first!