No specific hotel recommendations are made, as most of the hotels are located in Zagreb centre (~20 min by tram from Kraš building). Please refer to Booking.com or similar on-line resources.
If travelling on a budget, it might be worth looking at many of the hostels around, for example Chillout Hostel Zagreb also offers double-bed rooms for 45 EUR/night (40 + 1 for taxes + 4 for breakfast).