The IWF wants to make it easy for web users to report what they find.
Web users are being urged to help spot illegal and obscene content online.
The Internet Watch Foundation (IWF) is running an awareness campaign to tell web users how to report images of child sexual abuse.
The campaign comes in response to IWF research which suggests 77% of people who find illegal content do not know how to report what they have seen.
Banner adverts, e-mail messages and information pages are being used to educate people about how to report.
Find and seek
Sarah Robertson, a spokeswoman for the IWF, said that in 2007 the organisation handled 34,781 reports from members of the public who stumbled across illegal content.
While some find links to illegal content from legal pornographic sites many people accidentally stumble across such material too, she said.
Many sites hosting images of child sex abuse were run by organised crime gangs who charged for access. As commercial concerns, she said, many advertised their wares via spam campaigns.
"People might get unsolicited e-mails and not know where the link leads and could end up somewhere they did not want to be," she said. "The message is that it's important that they do report it to us."
Illegal content can be reported via the IWF site
Illegal content, be it images of child sex abuse, obscene pornography or race hatred, can be reported by clicking a big red button on the IWF home page.
Those finding illegal content can report what they have found anonymously or can leave contact details if they want to find out what has been done about the pages they found.
Many other sites are running banner adverts, circulating e-mail messages and placing notices on intranets inside organisations letting people know how to report what they find to the IWF.
The IWF monitors publicly viewable illegal content and relied on members of the public to alert it to the new sites traffickers in child sex abuse imagery have set up.
Ms Robertson said the work of the IWF had led to less than 1% of child abuse image sites being located in the UK.
The organisation produces a list of sites known to host illegal material that is circulated to net suppliers to ensure that UK users cannot reach these sites.
Ms Robertson cautioned concerned net users to leave it to the IWF to chase and shut down sites hosting illegal content.
"It's an offence to seek out this content to view it for any reason," she said. "It's against the law."