training is done once a week... check it on your weekly schedule page found on the rules link...
/BBWeb/rules.aspxplayers must have 48 minutes of game time (league game and cup/scrimmage game) before the training time...
you may see how many minutes your players have played through the weekly stats link found here
/BBWeb/weekStats.aspxthe pop-up arrow can be found besides your players skill at the rosters page... or at the player page... when your player got a pop, it means that the player received a level up in that skill...