The reception will take place in the "Studentenhaus" on the Karlsruhe university campus. It is marked with the number 01.12 (Mensa/Studentenwerk) on the map of the campus.
The busses will end south of the railway station. Then you go trough the station to the Northern exit, where the trams start.
Use the timetable of the "Deutsche Bahn AG" to plan your train travel.
By Car
Type the name of the place you come from and click the "Routenplaner" button (and later on "weiter") - you will get the detailed way to Karlsruhe and a map (in German)
Weather
Don't expect too much, it is November - but it may be better than you think (we hope...)
One of the best weather forecasts for Karlsruhe is www.suedwest-wetter.de. It is in German, but you are certainly able to understand the pictures ;-)