Labour has launched a website featuring "education materials" on how members can confront racism, with antisemitism the first kind of discrimination highlighted.
In an email to party members, leader Jeremy Corbyn admitted that "anti-Jewish bigotry has reared its head in our movement" and a "small" number of members held antisemitic views.
Mr Corbyn added: "Hatred towards Jewish people is rising in many parts of the world.
"Our party is not immune from that poison - and we must drive it out from our movement.
"While other political parties and some of the media exaggerate and distort the scale of the problem in our party, we must face up to the unsettling truth that a small number of Labour members hold antisemitic views and a larger number don't recognise antisemitic stereotypes and conspiracy theories."
Mr Corbyn said the worst cases of antisemitism included "Holocaust denial, crude Jewish-banker stereotypes, conspiracy theories blaming Israel for 9/11 or every war on the Rothschild family, and even one member who appeared to believe that Hitler had been misunderstood".
He admitted the party has a "real problem" with anti-Jewish racism and had been too slow in processing disciplinary cases.
The material includes "basic tools" to identify and call out antisemitic stereotypes and conspiracy theories, as well as guidance on how to avoid antisemitism when criticising the Israeli state and definitions of terms such as Zionism.
A party spokeswoman said: "The Labour Party has developed political education materials to deepen understanding of anti-Semitism, which is rising in our society and around the world.
"Today we are providing members with some basic tools to identify and call out anti-Semitic stereotypes and conspiracy theories, and more education materials on anti-Semitism and other forms of racism and bigotry will follow."
Labour has been engulfed in a row over the scale of antisemitism in the party for months, with Mr Corbyn accused of not doing enough to root out the problem.
But the party has said it is taking "decisive action" on the issue and has doubled the number of staff dealing with complaints.
An emergency meeting of the shadow cabinet will be held on Monday to discuss the row.
Mr Corbyn's deputy, Tom Watson, has launched a bid to toughen up the party's rules to make it easier to expel members for antisemitism.
On Friday, Sky News reported that Mr Corbyn's top aide instructed party officials to compile a dossier setting out how Labour's highest disciplinary body could be challenged.
A Jewish group claimed the leaked emails show the party's leadership want to "interfere" over antisemitism cases and are "not prepared to let the NCC [National Constitutional Committee] be independent".
But a party spokesperson said the messages were "entirely proper" and "show no attempt to interfere with any individual case".
Meanwhile, one of Labour's frontbenchers has defended the party's candidate in Uxbridge and South Ruislip, who is attempting to unseat Boris Johnson, over "disgraceful" tweets the contender sent as a teenager.
Ali Milani, who is standing for the west London seat at the next general election, tweeted in 2012 and 2013 that Israel had no right to exist, called TV presenter Piers Morgan a Zionist and wrote: "It will cost you a pound #jew."
Speaking to Sky's Sophy Ridge on Sunday, shadow justice secretary Richard Burgon said Mr Milani had apologised for the tweets.
"Quite rightly he has apologised for those tweets, and those tweets that are disgraceful he did when he was a teenager," he said.
"He has been on a programme of learning since then and, in fact, went to Auschwitz to learn more about where prejudice comes from and where prejudice against the Jewish community can lead."
Mr Burgon added: "I'm sure there are plenty of things Boris Johnson did as a teenager which if you applied that rule would rule him out from being prime minister.
"In fact, there are plenty of things that Boris Johnson has said and written more recently, including whilst he was an MP, including whilst he was mayor of London, including whilst he was in the running to become prime minister, which actually render him unacceptable and unsuitable to become prime minister."