There are several libraries in Prague that you can use.

Charles University libraries

The central catalogue can be found here: http://ckis.cuni.cz

Faculty of Arts libraries

General information can be found here: http://www.ff.cuni.cz/home/about/library/

Literature related to Romance languages can be found in the Library of Romance Studies: http://krs.ff.cuni.cz/en/

Main literature for al BA programmes, dictionaries, textbooks, etc. are stored in Library of Jan Palacha: http://kjp.ff.cuni.cz

National library

http://www.en.nkp.cz/

Municipal library of Prague

https://www.mlp.cz/en/

Libraries of cultural institutes

Instituto Cervantes (http://praga.cervantes.es/es/biblioteca_espanol/biblioteca_espanol.htm)

Institut Français (http://www.ifp.cz/Mediateka,247?lang=fr)

Istituto Italiano di Cultura (http://www.iicpraga.esteri.it/IIC_Praga/Templates/Pagina_Interna.aspx?NRMODE=Published&NRNODEGUID={8FB39623-5803-4BC6-9599-B20DFE136D0D}&NRORIGINALURL=%2fIIC_Praga%2fMenu%2fLa_Biblioteca%2f&NRCACHEHINT=NoModifyGuest)

Instituto Camões (http://www.institutocamoes-praga.cz/knihovna_port.php)