Evans said that while working at the Sunday Mirror starting in 2003, he was given the phone numbers of celebrities and told to "crack" them.
"Principally I was tasked with covering news events, investigations, undercover work, latterly with hacking people's voicemail," Evans said.
He said that in late 2004 later met then-editor Coulson about a job at the News of the World, and told Coulson he could do "stuff with phones" — though he did not use the word hacking.
"I got onto voicemails and interception and I told him I had a lot of commercially sensitive data in my head and how things worked at the Sunday Mirror and I could bring him big exclusive stories cheaply," Evans said.
Evans said he started work at the News of the World in 2005, and was given a list of dozens of names including model Elle Macpherson, former Spice Girl Geri Halliwell and king of pop Michael Jackson. He said he was told "to hack the interesting names on there."
He said he had accessed voicemails more than 1,000 times in all while at the newspaper.
He was eventually caught after using his work phone, rather than a disposable pay-as-you-go cell phone, when he tried to listen to the voicemails of designer Kelly Hoppen. She was able to trace the call back to him.
Murdoch closed the News of the World in 2011 after details emerged of the scale of its snooping on celebrities, politicians and others in the public eye.
The police investigation spawned by the revelations initially focused on Murdoch's papers, but has spread to take in other companies, including Trinity Mirror PLC, which owns the Sunday Mirror and the Daily Mirror.
In a statement, Trinity Mirror acknowledged Evans' guilty plea and said "it is too soon to know how this matter will progress."
"We do not tolerate wrongdoing within our business and take any allegations seriously," it said.
The company's shares fell more than 3.5 percent to 1.83 pounds ($3.03) Monday afternoon on the London Stock Exchange.
The Daily Mirror was edited between 1995 and 2004 by CNN interviewer Piers Morgan, who told a British inquiry into media ethics that he was not aware of any phone hacking while he was there. The head of the inquiry, judge Brian Leveson, called Morgan's claim "utterly unpersuasive."
The jury at London's Central Criminal Court also heard evidence Monday from phone-hacking victim Jude Law, who was told for the first time that a close family member allegedly sold stories about him to the tabloid press.
The "Sherlock Holmes" star was for years a favorite of Britain's tabloids, which reveled in details of his relationships with designer Sadie Frost and actress Sienna Miller.