Always use acceptable and polite language. Also make sure that any pictures or videos you upload are acceptable. Better check with your teacher first. Online work is NOT private. Never say or publish anything that you wouldn't mind seeing on the school bulleting board, or in the local newspaper or being seen by your parents and relatives. Remember that, apart from yourself, you are also representing your school, city and country in this project.
The common language in this project is English, so use it for all the different communications - discussion forum, blog posts, comments on photos or other members' pages. This is NOT a private, social network to send comments to other members from your own school in your own language.
Are there any young people out there, who feel they have learnt something valuable from the time they have spent on social networking sites?