IRS spokeswoman Judy Monahan in Seattle said online help will be available at www.irs.gov. as long as people need it.
She said the "1040 Central" link will answer many people's questions.
It provides highlights of tax-law changes and tax tips, lets people know common errors to avoid and even lets people know what to do if they don't have the cash to pay their obligation. The IRS takes American Express, as well as Visa, MasterCard and the Discover Card.
The IRS also allows people to authorize the government to withdraw money from their bank accounts, Monahan said.
Taxpayers can authorize electronic withdrawals when requesting extensions by telephone, she explained, noting that extensions extend the filing date, not the day any outstanding taxes are due.
The toll-free telephone number (888) 796-1040, will operate until 3:30 p.m. Alaska Daylight Time, she said.
The www.irs.gov site also provides links to tax forms and instructions that people can download.
For people who don't have access to the Internet, the IRS has recorded messages covering about 150 topics at (800) 829-4477.