As a reminder, the bus leaves from the airport at 10:30am on Monday, will stop at Ismaning a few minutes later, and then will return Friday afternoon. Details on the bus will follow. The information below about traveling to Ringberg by train is only for people who cannot take the bus, or for traveling around Munich before and after the workshop.
The Deutsche Bahn and MVV websites are great for looking up train and bus schedules, routes, and prices. Deutsche Bahn includes the entire German rail network (plus international), MVV is local Munich transport. The sites are easy to navigate, so please look at them first if you have questions.
http://www.bahn.de/p/view/index.shtml
http://www.mvv-muenchen.de/en/home/index.html
Within Munchen, most fares cover all public transport (trains, trams, buses) within a certain region for a full day. The most common fares are Innerraum (Inner Rim, 5.40E), Aussenraum (Outer Rim, 5.40E), Gesamtnetz (entire Munich network, 10.80E), and XXL (7.30Ecovers from Munich to Garching and Ismaning). Most fares have a partner option that typically covers up to 5 people for the price of 2. The system works on a semi-honor system, with infrequent checks and 40 E fines.
TICKET: Purchase a ticket to Tegernsee for 19.50E, or a Bayern-Ticket Single for 21E. This ticket gets you around anywhere in Bavaria, including local transport and excluding high speed trains, for the full day after 9am.
TRAIN: At the airport, follow the green S signs to the S-bahn. Take the S1 or S8 to Donnersbergerbrücke and switch there to the BOB train (typically platform 2) to Tegernsee. Be careful, as half of the train goes to Lenggries and half goes to Tegernsee. You'll have a chance to move cars later in the journey. Go to the end of the line, take a cab to Schloss Ringberg.
FREQUENCY: BOB trains run every hour at :13 past from Donnersbergerbrücke. The S-bahn runs every 20 minutes. Total travel time is about 2 hours.