How do I get a well-rounded understanding of chess openings? So, it was inevitable. I am making progress in the middle-game. I understand positions better and my tactics continue to improve. My end games are still solid/superior for my skill level so I generally get better as the game goes on.

However, now my opening play is suffering. I just get trounced on many openings. Many of the gambit openings just blow me away, particularly the King's Gambit, but others as well.

If I can survive the first 10 moves, I usually win, but there are so many traps in those first 10 moves. I have a good understanding (went through all the chessmaster lessons) of opening principles. I also understand a lot of the basic tactics in the openings.

But it's time to buckle down and study the chess openings and understand them. However, I am not an expert/master by any means (class C/B player), so I just want a more broad understanding.

In addition to my tactics/endgame and positional studies, what should I be studying in the openings to get a good understanding?

Thank you!

To get some ideas of what I currently play:


As black, against new players I will play Petrov's Defence. This
is one I know well. I only like to play this for longer games, as for
blitz games the lines get too complicated to play well. 
I enjoy the Ruy Lopez from both sides. Most of the standard lines work out well.
Against the King's Gambit, I always accept and then struggle mightily
to get my king to safety.  
As white, I like to sometimes play the
London System and sometimes go for the Ruy Lopez lines myself. 
I am not a big fan of the Indian openings, although they generally don't
cause me much trouble, they just aren't as fun. The fianchettoed bishops take too much of the action
I sometimes will play the Italian game instead of the Ruy Lopez, but it tends to lead to less exciting games.


In general, I like balanced games that can shift between open and closed, as being able to find the right plan is where it gets really exciting. I want to maintain as many options for as long as possible and not be locked down into any particular plan too early in the game.

Most of the time, my problem isn't when things follow normal theory; it's when some trick is played. Or even when the normal line goes wildly against intuition (I've seen some openings books where the standard line is random-looking pawn moves).
One book that I think you might find useful, both at your current playing strength and as you improve, is Mihail Marin's Beating the Open Games. It is a repertoire book for Black based on 1. e4 e5, and it covers all book openings White can use in reply except for the Ruy Lopez. (So for a complete repertoire, you would want to pair this with something on the Ruy Lopez. Not coincidentally, Marin has one of these as well.)

One particular from the book that touches on an opening you mention in your question: it recommends, as I did in an earlier comment, declining the King's Gambit with the fairly quiet 2. ... Bc5, ignoring the free pawn, calmly developing a minor piece, and not insignificantly covering the a7-g1 diagonal that White's first moves have opened up, potentially causing some development headaches for White. Thanks to the fact that Marin's book is based on his own playing repertoire, it offers a pretty consistent and coherent approach to facing the various non-Ruy Lopez openings - e.g. this 2. ... Bc5 response to the King's Gambit fits in well with his recommendation against a "deferred" King's Gambit via the Vienna Game, 1. e4 e5 2. Nc3 Nc6 3. f4 Bc5 - and it is an approach that generally steers clear of the wild and crazy.

One nice feature of the book - and this is mainly why I think it could be of use to you at your current playing strength and as you develop - is that it very cleanly separates a discussion of typical strategic ideas and considerations for each opening from an MCO-style table of theory for each, the latter of which you can choose to use to whatever level of detail you like (or ignore almost entirely) for the nitty gritty study of opening lines. The more idea-centric prose section on each opening alone can give you plenty to chew on.

Bottom line, it's a very well-executed book that, from how you've described your chess self, might be right up your alley in terms of its 1. e4 e5 recommendations. If you search around a bit, you'll find that Marin's chess writings are quite highly thought-of, and I think that reputation is well-deserved. Since I know you're familiar with Silman, here's what he had to say about this book:


  Beating the Open Games, joined with A Spanish Repertoire for Black, is the greatest repertoire book(s) ever written for players 1800 right to grandmaster. Marin's legend as a serious chess writer seems to grow every time he puts his fingers on a keyboard.


Lest the mention of 1800 give you pause, given that you describe yourself as a C/B player, note that others just as easily give a lower floor for it, e.g. Carsten Hansen writes, "This book provides something for every level of player, from around 1500 to even strong grandmasters."