Well, am writing from the Netherlands where am studying.I got some information here in 2009 and i acted upon those information without wasting time and thank God, the result was positive.The better part of the story is that, i did all documentation myself although if you pay your school fees here in the Netherlands,the school would process your visa.
Now, there is one school in Poznan,Poland known as University of Economics,Poznan. The school is cheap and needs international students and the application is open now.The course is International Business and its in English so no worries.The process is very easy, fill the form online and print it out,then attach all your credentials.But first, you would need to validate your credentials at the federal ministry of Education,Abuja.Then from there to Federal Ministry of Foreign Affairs because all credentials going out of Nigeria needs to be validated at the federal ministry of foreign affairs.When that is done, you would call polish embassy that you want to lagalise your credentials because your credentials need to be stamped authentic in their embassy.
To cut the story short, read from the school website.(http://www.ue.poznan.pl/study/)
Dont give money to anybody!
The dont hae any agent anywhere!!
do it yourself!!!

If you need any assistance,[email protected] but please read from the school website first.Thank you.