Including half of your yearly s.s. checks, you can make up to $25,000.00 if single or married filing separately or $32,000.00 if married and filing jointly. (as of 2009.. 2010 filing may be more or less) Refer to form SSA-1099 when mailed to you this year (before tax time)
There is no limit to earn money if you are managing your finance part smartly. You can invest your money in high yield investment plans, so that you can get high returns.
It depends on you and your working capacity. If you are really want to do something then you can do many thing, but you must go for mangerial work, like open a shop or a restaurent and handle only management and hire some workers
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