Within Europe: Fly to Cologne/Bonn (CGN) (Germanwings, HappagLloydExpress, LTU, Air Berlin are particularly cheap). From there take the express bus to/from Bonn main station (travel time approx. 20 minutes, costs 6,50 Euro). If you tell me, you can get out immediately at the first stop (that's closer to the university and my home). I'll come and pick you up there.
For general infos on public transport in the Köln / Bonn area see VRS and its Timetable search.
From the main station to my home (by tram 61 – Timetable)
Take tram 61 from the main entrance of the train station. You need a full ticket – currently 2,40 €. A vending machine is at the station, another one in the tram. For the one in the tram you need coins, the one at the station also accepts banknotes.
Get off at station “An der Josephshöhe”
Walk 200 meter to my home: see below.
From the university to my home (by bus 628 Timetable)
Take the bus 601 from the station on the right-hand-side when you leave the university. Ask the driver for a full ticket – currently 2,40 €.