Depends on your style of play, playing by principles is the best thing to go by, 'cause as I'm sure you're well aware of even the openings go into an imense amount of variations.
As a tactical player, I like a lot of traps, rather than any particular strategy of finesse, so I play games like the Smith Morra, Danish Gambit, and if I'm feeling cheeky, Kings gambit (all e4 gambits for white, e4 being considered an aggressors opening).
As black I play Scandanavian against e4(e4, d5) but after exd5 I play Nf6 aiming for a lead in tempo and development (rather than many I've seen take with the Queen which always seemed silly to me).
Against d4 I play c5, called the old benoni, not a lot of our levels are familiar with it, and if they play e4 after (aiming for smith morra gambit) e6 leading to a game called the "Franco-benoni". The stress in these kind of games generally comes when white plays d5 (after c5) and black must prevent whites pawn advance whilst utalising it to undermine white.
c4,b4 (polish),b3 and g3 are my personal weaknesses.
If you like closed games, d4 and c4 are supposed to lead to strategical (subtle) play ( I think, don't quote me).
As for names... YOU MUST LEARN SICILIAN, a bane in my earlier days and now I love it. After e4,c5 Nf3 the mainline is d6, but try a7 (the o'kelly variation) after white d4, take the pawn with cxd4 then when white recaptures with the knight (Nxd4) e5! and you've gained tempo and a few traps on the wing.
Ruy Lopez, a good one worth learning if you're gunna play e5 responses to e4, maybe look into the italian first, just my opinion, italian can lead to the fried liver attack. Queens Gambit, worth a look at, but I found it boring to be honest, (that and I never play a d5 response).
Youtube is full of resources, I reccomend a guy called matojelic, doesn't really go into depth of openings so much but has a wealth of games he comments and annotates and playlists of game types of old grandmaster games. That and he's cool as fudge, everybody loves him.
Also "Dereque Kelley" goes in depth about openings specifically, and is probably what you'd be looking for when looking into particular openings.
Hope I've been of some help
I am a 1500-ish player, hoping to make it to the 1800-ish range (and maybe beyond someday, but that's a decent initial goal). I've got a couple Silman books to go through (The Amateur's Mind, and How to Reassess Your Chess), and that's my next step.
However, I still sometimes lose games due to making a complete hash of the opening. "Control the center" and "develop your pieces" does a lot for you, even in unfamiliar lines, but there's still a lot of traps to fall into.
I don't think there's a whole lot of value in a player at my level spending a whole lot of time studying openings in depth; if I ever reach 2000 and want to make further significant progress it will be time for some serious opening study, but not at 1500.
But I would like a basic opening repertoire that would generally get me into a relatively even middle-game. And it would be nice to have some basic understanding of the positional objectives I should be pursuing with each opening.
So - what openings should I have some knowledge of? For e4, Sicilian, Ruy Lopez? For d4, Queen's Gambit?
Also, if you have any useful links that explain the logic behind one of the openings I should know, the main variations, and the positional goals each side should be pursuing, that would be appreciated too.