I have never had a teacher or anything. I have taught myself all I know from books and playing online. Nobody ever masters tactics enough!!! Ken Smith said years ago if you're under 1900, your first, middle, and last name is tactics.
The first three books I read were by Seirawan and Silman. Play Winning Chess is the introduction to chess, time, space, structure, etc. Book 2 is Winning Chess Tactics. It has examples of many different tactics and has details about looking for tactics. Book 3 is Winning Chess Strategies. It goes on to forming plans and such.
At the time, there were only 4 books ( 4 was Winning Chess Brilliancies - which is excellent but advanced). Another good book for learning planning is How To Reassess Your Chess. It is all about spotting the differences in positions and formulating plans around them. He later wrote The Amateur's Mind, which is him asking his students questions about positions. He then explains the misconceptions they have in positional analysis. It is a very good companion. These books should give a good solid positional foundation. Phase 2 is learning aggressive chess. Ken Smith suggested taking up gambits. They increase your tactical ability and really give you a fighting spirit. When your a pawn down in a hopeless position, you learn to really dig and claw your way back. It's not really about the credit of the gambits, it's more about learning to make a fight of it and seizing every opportunity. I went from 1700 to 2000 just studying gambits and tactics. I still haven't studied the ending all that well. I've mostly learned the endings I know from mistakes in thousands of blitz and other timed games. If your a piece up, in the ending you don't need theory.
I'd say the next phase is the really hard one. I believe you have to look really deeply at the games of great players and try to figure out what's going on. I'm trying to do that now. I mean really digging for every detail. It takes a lot of patience and hard work, but I think it can be done. I have over 400 chess books and don't need 90 % of them. The old great players didn't have all these different author's views. They studied games and played. That was it. I hope this helps at least a little.
I LEFT OUT THE MOST IMPORTANT PART. CHESS REQUIRES STUDY, PLAY, AND LOTS, LOTS, LOTS OF EXPERIENCE (AT LEAST FOR THOSE OF US THAT AREN'T NATURAL GENIUSES).
Best of Luck
P.S. Here are two of my favorite enjoyment books.
Chess For Tigers --- A good book that is really fun. It has coping with time pressure, playing stronger opponents, trapping heffelumps, and all sorts of goodies.
Winning With Chess Psychology is the other one. The title may not be exact, but it is by Pal Benko. It has the different psychologies players used from Lasker all the way to the modern day. One example, is Lasker would play for the initiative against Frank James Marshall because he always like to have it himself. There are some nicely annotated games in the book, including a 1.g3 win over Fischer.