Petrov's defence

There is a book coming out by Quality Chess on the Petroff in a few weeks (not 100% sure of the exact publication date, but it's the next book coming out by them).

There is also "The Petroff: Move by Move", which is probably an easier book to start with than the Quality Chess product, though you should probably get both.  The first more for the ideas, but don't pigeon-hole yourself to Lakdawala's lines, you'll want to expand horizons with the book from Quality Chess.

There was an old book in the 2000s by Everyman that was pretty much objective and covered all lines.  If you can get a hold of that one, I used to own that book until I gave it away.

The Petroff used to be my backup to the French Defense, but I pretty much play the French exclusively now.

@ThrillerFan Thanks a lot! I also play the French but I wanted to change a bit and try something else. I will try to find those books

Do not be surprised if you end up in a French.  I faced it a lot actually!

1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 and now, instead of the main lines, 5.d4 or 5.Nc3, White plays 5.d3 Nf6 6.d4 d5 and you are in an exchange French with 4.Nf3 Nf6, both sides 2 moves behind.

For a number of recent years (I'm not sure how many) the women's world champion, Ju Wenjun, uses the Petroff as her main 1 e4 defense. She plays the French some. Against 1 d4 her main defense is the QGD. 

With the white pieces she opens 1 d4 2 c4. 

I like her repertoire and considered playinig it, but instead I'm using the Keep It Simple 1 d4 book's repertoire, and when black I'm playing the Tarrasch Defense and 3...Qd8 Scandinavian. 

I played the Petroff Defense for several years (after quitting the Sicilian), and it is extremely effective against mid-level (B- and C-rank) players, who can't stand the early tension, and tend to blunder in resolving it.  However, I found those who know the main lines (and most A-rank and just about all Expert-level folks know them) can stop black from getting the kind of counterplay that I really wanted.

It's definitely more fun than a Ruy Lopez, and in my view it offers black better chances than some of the tamer 1. e4 defenses.  I don't play it often anymore, mainly because I went full hypermodern with my openings (which Petroff is not), but it's perfectly solid.

@ThrillerFan I saw that in couple of games, if I remember, it happened at the candidates as well. @Dsmith42 I know that it has a reputation of beeing drawish but I also agree that on some intermediate level it can give chance to black and even on top level Caruana plays it with success.

I hate to play against it. So yes, a good secret weapon.