I'll tell you all the things I wish I knew when I got my Boxster/before I got my Boxster.
1)
http://www.pelicanparts.com/boxster/boxster_tech.htm This is an AWESOME resource for pretty much everything. Read through all the titles and read the ones you want to know more about. You will learn a lot.
2) Like you said, drive it for a few months before doing anything to it at all. I'm talking 4 months minimum so you have time to really learn about your car.
3) Repairs are expensive, make sure you have a good mechanic to go to. Make sure you can trust them.
4) Boxster people are cool.
5) I change my oil every 6-10k and I use synth.
6) It will be more fun that you think.
7) At first I didn't like the back end of the Boxster, but when I bought one, everything about it started to grow on me. The car is really really pretty.
Enjoy