I bought this DSLR as my first one about four years ago. Till date I am yet to find a reason to uprgade it. Ofcourse the latter version have improved a lot, but 5100 is good for a part time amature photographer.
The camera battery life is awesome, apart from the kit lens, I have a 50mm and a tamron 18-200.
It is easy to operate if you know what you are looking for. Go through some basic videos on photography on youtube to understand the concepts and you will in no time be clicking awesome photographs. If you do not have budget for the latest entry level DSLR, I would recommed you to look out for this camera.
All the best with your hobby.
