From Zurich Main Station by tram to Stockerstrasse (tram 6, direction Bahnhof Enge; tram 7, direction Zurich Wollishofen; tram 13, direction Albisguetli), then a five minute walk along the Beethovenstrasse. Or by tram 11 (direction Rehalp) to Bürkliplatz, then a five minute walk along the General Guisan-Quai.
Address: Kongresshaus Zurich, Claridenstr. 5 - 7, CH-8022 Zurich

Map of Kongresshaus Zurich at   map.search.ch

Map of Kongresshaus Zurich

Usefull links:
Kongresshaus Zürich
Schweizerische Bundesbahnen (SBB)
Zürcher Verkehrsverbund (ZVV)
Zürich Tourismus