Parents can pre-register on Wednesday for the Government's Tax-Free Childcare scheme, which launches at the end of next month.
The initiative will begin on April 28 for parents of children aged under two, and will then be rolled out over 2017 in a move ministers say will cut childcare costs for working families across the UK by up to £2,000 per child per year, or £4,000 for disabled children.
From September parents of three and four year olds in England will also be able to apply for a 30 hours' free childcare offer worth some £5,000 per child, the Government said.
Chief Secretary to the Treasury David Gauke said: "This Government is on the side of working families and our childcare support will cut thousands of pounds off bills for millions of households, as well as supporting parents to return to or remain in work.
"The new Childcare Choices website provides busy families with options that suit their needs, so they can clearly see which childcare offer works best for them.
"For the first time, we have brought all the childcare options together to make the process easier and simpler for families and childcare providers."
Education Secretary Justine Greening said: "Affordable childcare and early years education are a vital part of how we can get our children on the right path, whilst also helping parents to be back at work, if that is what they want.
"Many parents are struggling to balance the cost of childcare against the benefits of being in work, and this Government wants to help.
"From today, parents can use the Childcare Choices website to find out what support is available for their family.
"Whether that's our 30 hour free childcare offer, Tax-Free Childcare or Universal Credit, the website is a quick and easy way for parents to choose the offer that's best for them and their children."
Eligible parents will be able to receive Government top-ups of £2 for every £8 they pay into their Tax-Free Childcare account up to a maximum of £2,000 per child, or £4,000 for disabled children.
The scheme is open to all working parents across the UK with children under 12, or under 17 if disabled, who are working and earn from £120 a week and less than £100,000 per annum.
Ministers say that two million working families will be eligible for Tax-Free Childcare.
Parents can pre-register for email alerts that will notify them when they can apply for the initiatives at www.childcarechoices.gov.uk.
The Childcare Choices website includes a childcare calculator so families can compare which options work out best for them.