For tax returns that claim EIC, the IRS is not allowed to start sending refunds until after February 15. If you use direct deposit, and nothing else delays your refund, they say it should be in your bank account by March 1. There will be an additional delay if you chose to have your TurboTax fees deducted from your refund.
Go to the following link on the IRS web site for more information about the factors that can affect when you get your refund, and a link to check the status of your refund.
Tax Season Refund Frequently Asked Questions