The things you can do to help overcome the lose of a loveone is help the person to remember that besides the lose, there are many beautiful things in the world. Some people, depending on the reason of the lose, may get involved in some helping others programs to help others to go through a problem and that gives allot of satisfaction. This also may help, through getting involved helping with others problems, to accept that things can happen in life and many things dont depend on us.
That is a really tough question. The most important things is to not try and 'solve' the families problems. Any family who loses a young one will be in incredible pain and that is appropriate because losing a loved one (especially a child) is painful. Simply reminding them that you care about them, that you are sad along with them, and that you want to help them as best you can. It is not your responsibility to make their pain go away-that may never happen. You can always listen to them and do small acts like doing the dishes or bring them a meal or go hang out with them so they are not alone and check-in with them.
Michael recommends the following next steps: