We can recommend several hotels:

To your information: there is a trade fair close to Bielefeld during the time of the meeting (10.-13.02.2014). Therefore the below given prices are not valid for all hotels.

Hotel Bielefelder Hof *, directly opposite to Bielefeld main station - room rates: single room 86,00 € / double room 92,00 € (breakfast included)

ARCADIA Hotel *, Niederwall 31-35, next to "Rathaus" and theatre in the city center - room rates: single room 75,00 € / double room 100,00 € (breakfast included)
                            already fully booked on February 11-13

Hotel Stadt Bremen *  Bahnhofstr. 32, in the city center - room rates: single room 64,00 € / double room 82,00 € (breakfast included)

Altstadt-Hotel  *  Ritterstr. 15, in the city center  - room rates: single room 58,00 € / double room 85,00 € (breakfast included)

B&B Hotel Europa Platz 2, 33613 Bielefeld, direcly behind Bielefeld main station - room rates: single room 50 - 75 € / double room 80 - 95 € 

Aappartel Boardinghouse Friedrich Verleger-Str. 1, 33602 Bielefeld, in the city center - room rates: single room 38 - 50 € / double room 65 - 80 €

Etap Hotel   Detmolder Str. 314, 33605 Bielefeld, 3km to city center, 9km to university - room rates: single room 39,00 € / double room 49,00 € (breakfast included)

Jugendgästehaus Bielefeld  Hermann Kleinewächter Str. 1, close to the city center - room rates: guests over 27 years: single room 48,80 € / double room per person 35,00 € / 3-4 bed room per person 28,80 € - guests under 27 years: single room 44,80 € / double room per person 32,50 € / 3-4 bed room per person 26,80 € (breakfast included) - a special identity card for youth hostels is needed, which is available at Bielefeld University 

Guesthouse of "Studentenwerk Bielefeld"   (53.00 Euro without breakfast (+ 10.00 Euro for a second person in the same apartment / common kitchen with another apartment) in Morgenbreede (on the university campus) - 

For more information about accomodation in Bielefeld: http://www.bielefeld.de/de/ti/uebernachten/

respectively http://www.bielefeld.de/de/ti/uebernachten/hotels/