Most of the tax law changes such as lower rates for tax brackets that were put in place for 2003 continue for 2007.

The standard deduction for 2007 is:
Head of household---$7,850
Married filing joint----$10,700
Married filing separate---$5,350
Single---$5,350

The child tax credit continues to be $1,000 for children under 17 years old.
The personal exemption is $3,400 in 2007.
The amount of net income from self-employment must be at least $4,000 to earn four quarters of credits for social security purposes. The website for this information is: http://ssa-custhelp.ssa.gov