The Schengen countries are: Austria, Belgium, Denmark, Finland, France, Germany, Iceland, Italy, Greece, Luxembourg, Netherlands, Norway, Portugal, Spain and Sweden. I do not believe that Poland is among the countries for which the schengen visa is acceptable. I would recommend that you check with the Poland Embassy or Consulate for confirmation before you leave on your trip.
Regarding your connection in Dublin, most countries do not require a visa if the time span between one flight and the other is short. However, your nationality is what really dictates in most cases whether a visa is needed or not while you are in transit.