Keep hitting the math books hard until October. If you haven't done formal logic yet, try to get it in now. Brush up on rhetorical logic as well. Learn the list of logical fallacies inside and out, and you'll be living on a whole different plane of existence than the overwhelming majority of your classmates.
When you get to Poland, find a tutor to keep you moving. There are plenty of grad students who would gladly help for about 6 Pounds an hour. It's a lot easier to keep moving if someone is constantly kicking you in the pants, and is available to help you if you get stuck. Line up a place to live in May. June at the latest. The best, and most affordable, places are gone after that.
As for neighborhoods, I would go with Szczepin/Mikołajów (Tram stops Młodych Techników, Plac Strzegomski and Zachodnia). Yes, you'll be living in a block, but the meighborhood is really clean and safe. Mostly retired engineers live here. The most important thing, though, is the trams. It take about twenty minutes to get from there to WUT, and there is a tram every four or five minutes (lines 10 and 33). Prices tend to be lower than the trendier areas like Biskupin, Ołbin, Sępolno or Krzyki, and the value is about the same as far as a student is concerned, so the value is good. Access to downtown and to stores is great.
Avoid Śródmieście and the Trójkąt Bermudzki areas unless you are experienced living in rougher neighborhoods. Their generally safe during the day, but at night drunks, both young and old, can make life unpleasant.
Stay about a month or two ahead of the curriculum, and always know the subject matter to be discussed BEFORE a lecture. The more you go in with, the more you come out with, and if you go in with nothing, you'll probably come out with nothing. Keeping ahead is also important just in case you get sick and have to miss lectures. Once you fall behind, it's incredibly difficult to catch back up again. Treat lectures as a SUPPLEMENT to your own self-guided studies.
Kind of a shame everyone seems to sound so cynical about it though.
Not exactly cynical, at least in my case. Just experienced. I did my own studies in the States, with graduate school at top-knotch schools in Germany, the States and Denmark, and six-month research stints in Israel, Greece and the UK. I've been in Poland for ten years, and work closely with all of the universities in Wrocław. On top of that, I mentor students, and know the situation very well. The Polish higher educational system in far inferior those I experienced during my own studies (even Greece). After ten years, I'm still in shock. The level of the practical courses is especially shocking.