Hired to teach?

So the high schools are writing finals this week, thus, me being a substitute, will probably be having the week "off". Being a recent grad and getting letters in the mail that have big sums of money owing on statements that come from the banks and various loan agencies is not a real happy thing. Plus, it is a balmy -45 degrees celcius today...not a real good start to the week. Then after lunch I get the call..."Hi Tyler, this is so and so at THE high school. We would like to offer you a full time teaching position for the second semester." As I try and sort through what has just been said to me the principle goes on to describe what comes next in the whole job offer process.
With a baby on the way and my wife due to go on maternity leave next week you could say, perfect timing. And now the sense of satisfaction as my child starts its life I can look it in the eyes and not feel like a dead-beat dad and actually support my family (wow, who would have known getting that University degree and racking up all that debt would have paid off so soon).
My issue is this. I am hired on full time for next semester. I will be teaching four classes in a school I have never been in, to kids I've never met, with staff I don't know and here's the kicker...I don't even know what the classes I am teaching are yet! I must have missed the how to teach a full load with no prep time class at university. The old sink or swim...ahhh isn't life grand. All I can say is I am grateful for the opportunity and hopefull that there will be some helpful people at the school I will be teaching at. Let the mayhem begin!