***I'd also like to open this thread up for anyone living/working in Poznan since I can't really find much from those within the forum.*** Let's feel free to open discussion with job openings, advice, and support.
Ooh, I'll bite.
Poznan is a very strange city - it's without doubt the business capital of Poland, yet multinationals are very reluctant to come here. Many students at my school are involved with property/shares/etc, which shows that there's work for this kind of thing here - yet barely any of them have had regular contact with native English speakers in Poznan. I really don't know why - even one of them is constantly begging for me to take her on a night out so that we can hunt down native speakers for her to practice on.
Kraków appears to be attracting much more in the way of English multinationals at least - why, I really don't know, but it's probably related to the popularity of the city with English speakers.
One thing that's notable is that there's a lot of German companies in Poznan - if you can speak German and (obviously) English - then a job should be easy to find.
I think the best bet in your case is simply to teach for half a year - it'll give you time to really find your feet in Poznań - and (no offence intended to many of the teachers on here!) teaching is light enough to allow you to investigate other things too. You might find that students are useful contacts too - although I have no interest in doing anything at the minute, so I don't know how true this might be.
To be honest, I'm really struggling to think of how else you could find something. I don't know of the expat scene here at all - or even if there is one. Apparently there's a bar in the Sheraton that's very English-orientated, but how busy/populated/useful it might be, I'm unsure. There's also a place called Coxy's according to the ever-useful In Your Pocket - but I've never been inside, and when I've been past, it's either been locked up or playing hideously loud and crap music that makes me flee to the nearest cafe.
But any questions, feel free to ask.