Spot on about tactics, Zappa. Nigel Short even suggested that he used primarily tactics to reach 2400! Now, he's likely exaggerating, but the point should be taken under advisement. :)
Silman's Complete Endgame Course (2007) uses a nice touch in that it's arrangement of topics is by ratings class need. If you want to be a C-Class player (USCF 1400-1600), you need to study and know everything through Part 4. If you want to be a B-Class player (1600-1800), then master all the C-Class material plus Part 5.
BTW, an interesting note is that he'd not recommend anyone spending hours learning to mate the lone king with B+N ... it just doesn't come up enough to make the effort worth while - spend the hours on something else.
any chess player likes to improve his play, recomending sertain books may help, but what we should look for is a plan, i have been trying to find one for the last year and there is certain book deticated for that. we should consentrate too much on tactics, it acount for 95% of chess play, you can do that by solving problems and puzzels, i mean thousends and thousends of them, it help improve pattern recognetion to a grait extend,you can read some introductory books about tactical thems like: chess tactics for tournamet players, winning chess tactics.. after that you can improve tactics by analysis and calculation of varations, books that may help include valery beim books,practical chess analysis, secrets of chess training, tactical play(dvoretsky)......
unless you are over 2000 elo forget about strategy books, becouse posional play needs a grait deal tactical and technical skills
another important path is endgame, you can start by chess endgame traing(rosen), trotsky, pendolfini endgame course...until you reach endgame manual, endgame analysis(dvoretsky). doing tha endgame is not just for playing batter ending, it help you get afilling of each paice pros. and cons. and relative value of each peice..
endgame and tactics could get you like 300-400 points in two years.