To get from the airport to the meeting location (Garching Forschungszentrum), the easiest way is to first take either of the trains from the airport (S1 or S8) to Marienplatz, and from there change to the U6 underground line (signs are in the Marienplatz train station) and take any U6 going to "Garching Forschungszentrum" (the last station). If you are checking into a hotel first, you should get off the train at the stop "Garching", the meeting is at the final stop. This will cost 10.80EUR for a 4 zone ticket, or 12.00EUR for a single day "Full network" ticket and will take roughly 1.5 hours.
To enter IPP, you should use the exit at the back of the train and go up the stairs; the entrance is right there.
Alternatively, you can also take a taxi from the airport to Garching Forschungszentrum or Garching town, which will cost 40-50 euro and take about 20-30 minutes. A map of the hotels in Garching can be found here.
Detailed information on public transport
If you are staying in either Garching or Garching-Hochbrück, you need to buy either a "Kurzstrecke" card (cost = 1.30€), which is valid for one trip in one direction, meaning you will need two per day. These tickets must be validated in the blue boxes near the platform entry before using the trains. The other possibility is to buy a "Streifenkarte" (cost=13€), which consists of 10 stripes, each of which is equivalent to one "Kurzstrecke". To use the stripes, you simply stamp the next unused stripe in the blue box.
For travelling to the city center, the U6 stops at several places towards Marienplatz, which is the middle of Munich city. If you would like to go there in the evening, or if you are staying there, it is better to buy a full day travel card (a single trip cost 4 stripes). To reach Garching (or the city in the evening) you should buy the Muenchen-XXL day ticket (a "Single-Tageskarte", cost=8.30€) which may be used as many times as you like in any direction inside the radius of Garching (Garching marks the boundary of one of the "rings" in the Munich public transport system). If you intend to go into the city in the evening, you should buy this ticket in the morning and use it all day.
Do not forget to validate your ticket by stamping it in the blue boxes when you get to the paltform! If you forget, your ticket is not valid and you may receive a fine of 40€. More information on the Munich public transportation system can be found here and timetables of the trains to and from Garching and Garching-Hochbrueck can be found here and here.
Location of meeting in IPP campus
The meeting will be held in the D2 building. As you walk in the main gate, continue straight for ~200 m (crossing the bridge over the small stream) and it is the second entrance on the right-hand side. A map can be found here.
The conference dinner will be held in Gasthof Neuwirt in Garching. It is situated near the southern exit of the U6 in Garching. If the weather is nice, it is also possible to walk there (distance = ~3 km, 30-40 mins duration) directly from the IPP campus. The location can be found here.