Back in the last 30 years, most of what's known as theoretical chess knowledge existed purely in the form of the printed word - chess magazines, chess books, Informants. These were the main source of information one can get on the latest trends in opening theory, or the presentation of great games played by the masters with great comments from the authors.
That trend was completely changed with the Computer Age - the use of chess databases, playing programs like Fritz or Rybka and instruction videos. The poor chess student is really flooded with tons of information coming at a ridiculous rate that it is near impossible to find the time to rummage through, let alone study, the essence of the material.
With time controls of 25 mins or less per player to complete the game, one wonders why is there the need to invest time and effort to learn chess when there is hardly enough time for the student to ponder about the plans and strategies one has learnt, hoping to find some use for it in their games?? Most games I reckon would mainly be decided on either tactical blunders or loss of material given en prise. To play well in the rapid 25 min time control, would it not be enough just to practice on tactical shots and play gambits? Do you honestly think the child will be able to do something like " Oh..White has just made the same error as XX did vs YY at the 20NN tournament so the finish goes like .."? Short of the player having a photographic memory (which does help in remembering loads of opening theory), to figure such things out within the time frame of a total 50 minute game is not possible in club play. Hence it is best to have games of 1 hour per side or more per player to give him/her the luxury of recalling the chess knowledge that has been learnt to devise the right plan of action. When this happens, the satisfaction of winning a game is far greater and thereby reinforcing the notion that chess is very much a thinking game, rather than the slow-motion version of an arcade shootout.
Is it therefore any wonder that today's children know next to nothing about reading chess books for improvement, or watching a video they can get their hands on? The chess culture that we've had for the past 30 years, seems to have been eroded over the last 10. How ironical, because it is precisely the last 10 years that chess information has been mushrooming and today I would say there are relatively few secrets left in the chess world of knowledge. Books and videos explain to a T what you need to know to play a specific opening, how to handle play in specfic pawn-structures like the Isolated Queen Pawn, tactical exercises online that you can practice to sharpen your skills. The only realm where knowledge is not so clearly digestible is in the endgame. Though computers today can work out endgame solutions of any position where the number of pieces on board do not exceed 5, it is near impossible to expect the human being to play that way. I see the endgame as the last bastion where human ingenuity is still called upon to win a game rather than the reliance of total chess knowledge to dictate the play.
Sadly, learning about endgames is the bitter bit of chess that even strong players do not enjoy, because of the lack of excitement in such positions and the cold clinical accuracy one must have to execute the winning routine. It is precisely in this realm that we can teach kids about the logic of planning. As in most theoretical endgames, a clear winning solution is presented even against best play by the opponent. Learning the methods can certainly help in understanding how the pieces work together towards the strategic plan. Learning tactics acheve the same end, albeit with a lot more excitement.
Hence I will focus on bringing in useful excerpts of good books that I've had the fortune to read over the last 35 years, for the young budding player in mind of course. I will start with Basic Chess Endings by Reuben Fine. Though its an old book,Pal Benko has revised it but the instructional part of it is crafted by Fine himself. I would not vouch for the analysis of moves as it has been found to have quite a few errors, but what I like about it is the way it offers advice on how to conduct specific positions with a few pieces.