Schengen question.
 

I have already looked through the other posts with questions regarding the Schengen zone but my situation is a bit different. I am currently living in Poland past my 90-day visa as an American, but I have a stamp that allows me to stay in Poland longer because I'm in the process of getting my temporary residency / work permit card. I don't have the card yet but have a chance to go to the Netherlands for the weekend. Will I get into trouble if they check my passport? Or trying to visit even though my 90 days has expired?

Ask an immigration lawyer, not this forum.

Do as menachem says, or check with the Dutch consulate in Poland.

I can tell you that I have a friend who applied for her residency here in Belgium, where I live. She asked the Dutch consulate if she was allowed to visit the Netherlands in the meantime, while waiting for her permit. They said no; if checked in the Netherlands they would put her on a plane to her home country as an illegal immigrant.

Technically you do not have a valid visum for the Netherlands at the moment.

There are no internal border checks in Schengen, so practically speaking you can probably get away with it. But should there be a spot check, or something happens and you come to the attention of Dutch police or border control, your illegality will come to light and you risk being deported, though that's unlikely. Having said that, the Netherlands are one of more fussy countries when it comes to implementing immigration rules, alongside Germany and Switzerland.

The Dutch regularly do passport checks on international trains.

Since you are waiting for a resident permit why risk being deported. There is nothing in the Netherlands so important as to risk that surely?

Oh, add Poland to the list of fussy countries. A recent traveller arriving at Polish border saw the boarder official actually count the days to make sure they haven't exceeded 90-in-180 days Schengen rules.