There's a help sheet so read that too. When you paste the players, go to the Scout sheet. In B6 through O19 cells you can define name and target skills for your player to reach. You can define 8 profiles. Above that define what coach level you have (E3). In X3 cell click on the drop down menu and choose which player you want to train. In AF8 cell choose your target skill profile you defined earlier and voila. Training regimen is created and customized just for your player :)
In AF9 you'll see how many pops the player needs to reach target skills. What's most important to you is C29 cell where the training regimen starts. It takes into account age, height, I think everything except potential but that's another story. So starting from C29 cell you see what do you have to train each week of the season, it displays it's projection when the player will pop (assuming sublevels start from scratch). s17w14 means season 17, week 14.OD for 1 means Pressure training for position 1 or PG. JS for 23 means jump shot for SG and SF. You get the picture.
Where I see this tool really valuable is when deciding what trainee to buy. I put in his skills, choose a target profile then scroll 3 seasons in training schedule and see his salary. If it's 20k, it's not good and the player is not worth training. But if it's 100k, wow. I want that kid. :)