A new form of help was released and you can find some useful features there.

Practice Tool is a new solution for players who wish to train their skills and better understand the mechanics behind League of Legends’ gameplay. It’s a single player experience without the need to set a Custom Game.

Official blog post lists several features of Practice Tool: Champion mechanics and combos, jungle practice, endless last hitting, item build DPS checks and map familiarity. You can check the details in the mentioned post and in-game. Oh, and there’s a trailer: