Eight out of 10 of the problems young people needed help with debt, benefits, housing problems and employment.
The charity said debt problems accounted for a third of all the enquiries it received from people aged under 25 during the year to the end of March, with personal loans the single biggest issue on which they sought advice.
Benefits problems made up a quarter of all enquires, with the group seeing a 40 per cent rise in people looking for advice on Jobseekers Allowance.
Around 12 per cent of all enquiries related to employment, while 10 per cent concerned housing issues, with a "very high" number of young people having problems with housing benefit and privately rented accommodation.
Gillian Guy, chief executive of Citizens Advice, said: "It can be daunting to seek advice if you have a problem - but more often than not, the sooner you tackle it, the easier it is to put right.
"Under-25s often have specific issues, so we've now pulled together lots of information you might find useful in one place."
She added that the website could also be viewed on mobile phones, enabling young people to access it while they were out.