And how much money you get back with your 401 K retirement plan?

I am assuming that your deductions for money put into the 401K is pretax, so you got the benefit of paying no taxes on it with each paycheck (typically no more benefit when you file).

However, you might qualify for a credit come tax time that is for people who put money into a retirement plan & they meet certain criteria (based on your income & age). It’s meant to encourage people entering the workfroce to put money into a retirement plan. Check out:
http://www.irs.gov/pub/irs-pdf/f8880.pdf

Otherwise, don’t do anything with your 401K until you take money out of it (hopefully won’t be until you retire, otherwise there are penalties).