Never really worked at it, does it make a big difference to the growth of your players?
I normally just buy the best coaches and players witht he best potential and they turn out well enough.
Is there a beginners guide around, or can some of you give me some tips?
The training and the tutoring of youths are the most important things to do if you want your player to get better (this is what I think

. if you have genie scout you will see that the potential ability of one player grows if his determination grows, and to grow determination you need to tutor the player. For example I play with Liverpool and I have tutored Martin Kelly with Jamie Carragher. Kelly not only have had his determination from 14 to 18 upgraded but also he improved his marking, tackling, agility, heading etc. Also I have put Kelly on a training regime and gave him individual training. In the end of the season my assistant gave me a report for the training in the past year and he was the player with biggest improvement. Since then I do this to every youngster, and there is great improvement.
However the training is important because, some players need different sort of trainings. Example, the attackers don't need goalkeeping etc, so as other player that is why the training is important in the game.