If you are arriving by air, most likely you are landing at Lester B. Pearson International Airport (http://www.gtaa.com/en/home/) which is about 20km west of the University of Toronto.
A cab ride during off-peak hours takes about 25 minutes; during rush hour (7:30–9:30 a.m. and 4:00–7 p.m) the ride takes from 40 minutes to an hour. Taxis from the airport charge a flat rate, approx. CAD53 to the University/Hotels (http://www.torontopearson.com/en/toandfrom/taxilimo/#) Limos are also available. The vehicles used by airport taxi and limo companies are pretty much the same; limos charge about 10% more than taxis.
Trips to the airport may be arranged in advance by calling an airport taxi company. Alternatively, you may take a regular city taxi to the airport.
Most taxis and limos accept credit cards.
You can also reach the University and Hotels by public transportation from the airport. Take the 192 Toronto Transit Commission (TTC) bus from the airport to Kipling subway station (the end of the line), then the subway to St. George Street. The fare is CAD3 (You pay when you enter the bus, exact fare or a token required; no additional fare is required for the subway.) The trip takes 50 minutes to an hour.
Toronto has another airport, Billy Bishop Toronto City Airport (http://www.torontoport.com/airport.aspx) which has a limited number of flights from the US. This is much closer to the city. The airport has a shuttle bus to the subway (Union Station) from which you take the University-Spadina line north to St George. Taxis are also available, fares will be around CAD15 to the University/Hotels.
Subway/Bus/Streetcar is operated by the Toronto Transit Commission (http://www.ttc.ca/). Cash fares are CAD3. The closest subway station to campus is St George. See the map (http://www.ttc.ca/Subway/interactivemap.jsp).
Taxis are a convenient way to move around the city. It is safe to hail a cab on the street, plenty of cabs are available on Bloor Street and St George. You can also sign up for Uber and get taxis from your phone (https://www.uber.com/).
Walking is generally safe in the city. All events are on campus or within walking distance from the conference venue. The longest walk is to the conference dinner (about 20-25 minutes). The dinner is near the St. Patrick subway station, three stops south from St. George on the on the Spadina/University line.