More than a third of 12 to 15-year-olds have faced some kind of cyberbullying, according to a government study.
Ministers are also launching an awareness campaign on the social networking sites used by many pupils.
Schools have been told they can confiscate mobile phones and how to get hurtful material pulled from websites.
Schools Secretary Ed Balls said cyber bullying was "insidious" and had grown with technology and changes in society.
Schools needed to get to grips with newer forms of bullying, he said.
Examples cited include threats, intimidation, harassment or "cyber-stalking", unauthorised publication of private information or images, impersonation and so-called "happy slapping".
Mr Balls also called for action against anti-gay bullying -calling for schools to promote a "culture of respect" and saying that "homophobic insults should be viewed as seriously as racism".
Ed Balls said: "The vast majority of schools are safe environments to learn in. However, we know that behaviour, particularly bullying, is a key concern for parents and bullying of any kind is unacceptable.
"Cyberbullying is a particularly insidious type of bullying as it can follow young people wherever they go and the anonymity that it seemingly affords to the perpetrator can make it even more stressful for the victim.
"One message that I want to get across to young people is that bystanders can inadvertently become perpetrators – simply by passing on videos or images, they are playing a part in bullying.
"We now have an advanced approach to cyber bullying, thanks in no small part to the co-operation with the industry, teaching unions and charities."
The guide being sent out to schools in England says cyberbullying can be an extension of face-to-face bullying, "with technology providing the bully with another route to harass their target".
But it says it differs in that it invades home and personal space and the perpetrator can use the cloak of anonymity.
Among the new guidance are tips for drawing up anti-bullying policies to cover cyber bullying, how to have offensive or malicious material removed from websites, and advice on confiscating equipment used in bullying, such as mobile phones.
Offensive weapons call
The new measures were developed in consultation with anti-bullying experts, mobile phone companies and websites including Bebo, MySpace and YouTube.
Teaching unions say children are not the only victims of cyberbullying and that school staff are increasingly falling victim to it.
Chris Keates, general secretary of the NASUWT teachers’ union, said teachers would be pleased that ministers had recognised the problem.
"Mobile phones capture videos and pictures of teachers at work," she said.
"The often distorted images are transferred to the phones of other pupils within the class, across the school or uploaded on to the internet. E-mails are used to abuse, harass and insult.
"Misuse of internet sites can destroy teachers’ confidence and professional reputation and provide yet another vehicle for false allegations against staff."
The union is calling for pupils’ mobile phones to be classed as potentially offensive weapons and for them to be banned during school sessions.
Mick Brookes, general secretary of the National Association of Head Teachers (NAHT), said: "Sadly, bullying is a negative feature of any society and will only be countered by strong action against bullies and a bullying culture.
"We would encourage all partners in the world of education to play a part in stamping out wanton actions that negatively affect the lives of others.
"Many schools harness the student voice, through student councils and other means, to counter bullying in the most effective way, because students are closer to the lives of their peers."
The ATL teachers’ union also backed the need for action against homophobic bullying – saying that it remained a "pervasive" problem in schools.
A survey for the union found that 70% of teachers had heard children in their schools using homophobic language.
Via: BBC News