This is what the IRS says about these kinds of benefits:
"Do not include in your income benefit payments from a public welfare fund based upon need, such as payments due to blindness. However, you must include in your income any welfare payments that are compensation for services or that are obtained fraudulently."
The payments should be reported, but they are not taxable.
By the way, you are probably going to qualify for the Earned Income Tax Credit (EITC), which is described here: http://hhsa-pg.sdcounty.ca.gov/FoodStamps/SpecialNotices/FSPG_10-01_Earned_Income_Tax_Credit_Outreach_Publications_2009.pdf
Finally, since you receive Cal-Works, you can obtain free tax preparation assistance and electronic filing from VITA, which is described here: http://www.irs.gov/individuals/article/0,,id=107626,00.html