I spoke with a friend who tells me about ITIL. ITIL agregates best practices in computer sciences (not only technical, but management, financial...). I think I will have a close study on it. So, I added two interesting links (the first one is in french, sorry for english people)
http://www.itsmf.fr/
http://www.itil.co.uk/
http://www.itsmf.fr/
http://www.itil