I would like to have some e-mail addresses of karelian's schools and companies. Mainly in kuopio, joensuu,lieksa etc. I would appreciate if you could help me.

You can find Joensuu schools and educational services through homepage of Joensuu city in internet: http://www.jns.fi/eng/index.html and there you see "services". There is information about The Center of Educational Services, If you press the arrow, you can have pages of different schools in Joensuu.
Other North Karelian towns and communes and there educational services you can find through "Province of Karelia: The homepages of the towns".
Different homepages of North Karelian companies you find through the same page: take "companies".
Other homepages of North Karelian companies you can find through the pages of Joensuu Science Park:
http://www2.carelian.fi/en/main.php .
The e-mail address of the office of employment services in Joensuu is: joensuun.tyovoimatoimisto@tut.mol.fi. From there you can have information for looking a job.