I'll be studying in Tampere as a master's student coming from abroad ( non-eu )

I already have the residence permit for a year ( to be extended ) and I'm already registered in system ( finnish identification number which has birth date numbers yymmdd-xxxx , for example ).

I have a summer job now in Finland, I receive salary and I pay tax to government, tax is deducted from my salary...
I'm not officially a student yet, because registration starts in late August 2010.
My question is,
If I get a part time job in Tampere, in educational institution or in a restaurant, whatever, what are the conditions of taxes? I have heard that %60 percent of my part time work salary could be deducted to taxes, in some conditions...

What are those conditions?

I, as a student soon, will want to get a part time job, because the government does not give a scholarship or any kind of grant ( KELA for example ), since I don't have a permanent permit, therefore it would be nice to get a part time job and earn money to support own living...
So what are the limits ?

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