If you want to read detailed reviews of smartphones and compare them with other phones then there are a few websites which are really good for this
1. http://www.gsmarena.com/ – Here you will find brand wise classification of smartphones and you can also compare phones. The reviews are really well written.
2.http://www.phonearena.com/ – an alternative to gsmarena
3. http://www.youtube.com/– for those who are curious to watch the unboxing and handling of the phone, youtube is the perfect place for this. You can search for any phone model and check out how it works. youtube is perfect for those who order phones online and have not physically operated the phone.
4. A couple of trustworthy websites for buying phones online in India:
5. For buying used phones in India