Undergraduate / 'Teaching the 10th grade's Informatics team' - Extracurricular essay [3]

In the summer 2010, I had the previlige privilege to teach the 10th grade's Informatics team of my high school. My jobs wereI were assigned to encourage the students, help them to absorb new knowledge and share with them my experience about competitions - try a different word, not sure what you mean. Firstly, I thought it would be easy for me to complete this job. But, when we started, teaching wasn't the simple task. - try to rewrite this sentence. I had to give the explainations, share my ideas about problems and answer all questions of nine students . Finding the relevant algorithms and concepts to introduce them was also very a complicated work. However, I used to be a member of this team and I understood that these students really needed my help. The more difficulties I had, the more passionate I became about teaching. So, I was really excited when these students received prizes in City Olympiad of Informatics. That summer, I not only improved the communicating skills, leadership but also learned the happiness in helping others.

Please help me check error(grammar, structure, word choice).
Thanks in advance!!

Good luck with your essay, i am no native speaker wish i could help you further though!