People continuesly go on about Sakura's uselessness.. So here are some things which directly contradicts her uselessness.
So she is one of the most useful characters in Naruto.
Thought I would let the base know that Sakura is indeed a very important and key character.
Despite her healing and moral support throughout the entire manga, Naruto Uzumaki would not be the man we see today. She has a very great impact on who he is and he would be dead if it wasnt for her.
During Sasuke's fight with Gaara, Sasuke became immobilized. This would allow Gaara to completely annihilate Sasuke, but Sakura stood over him and made Gaara snap and grab her. Thus allowing Naruto to scoop Sasuke up.
Sakura was able to save Kankuro's life, which in turn he was able to give them information on the two Akatsuki who took Kazekage Gaara.
The combined powers of Sakura and Chiyo was enough to overcome Sasori and as a reward he gave Sakura very important information about a spy. This spy is spying on Orochimaru, which would lead closer to Sasuke however the spy was a double spy.
She was able to find and figure out an assassin in the medical camp. This assassin was a Zetsu transformed into Neji. She figured out the Zetsu's power and had it relayed to HQ. Very important being there is a whole army of Zetsu.
-Along with this is Alliance wide healing, healing mostly everyone at least once.
-Healing Naruto and boosting alliance morale.
And now you know for fact she isn't useless.
I'm sure there are many more, these are just quick things I thought of.
Thanks for reading!