ECO-B
Sicilian Defense
If you're around 1200, I don't think you should seek opening books just yet. Your time would be much better spent studying more tactics, going over master games, etc. I don't think opening books are required until at least 1400 live rating.
Starting Out The Sicilian by John Emms. I believe the 2nd edition just came out recently.
Yes !
I have this book . It is excellent if you want on overview of all white and black main tries .
It gives you the main positional ideas and strategies for both sides in each variation without being biased to one side or other.
If you don't already play the sicilian it will help you decide which variation you want to play ( there are lots , it may seem overwhelming at first ) , but this book is an excellent starter .
check it out here

I've heard from a senior player (around master level) that "sicilian should not be played by beginners or people under 1600 elo. It requires too much theoretical study and is not ideal for novices."
Is that a valid reasoning?

Is that a valid reasoning?
It is if you're a 1200 player trying to play it against 1600+ players. If you're a 1200 player trying to play against 900-1300 players, it will make for some interesting games and probably a few more wins once you get the hang of a couple of lines. If it gets you to think more in the opening instead of winging it blindly and looking for tactical shots when there may not be any, what's the harm?
Can anyone recommend a book for someone who wants to begin seriously using the Sicilian Defense?