You can find information about workshop registration at http://www.acl2013.org/site/registration.html and register from the link there. CMCL is a one-day workshop. Early registration ends June 30, 2013, so register soon to get the lower price!
Travel & general information about conference venue
CMCL is collocated with the Annual Meeting of the Association for Computational Linguistics in Sofia, Bulgaria. General information about getting to Sofia can be found here: http://www.acl2013.org/site/info_general.html and information about getting around in Sofia can be found here: http://www.acl2013.org/site/info_travel.html
Accommodation information can be found here: http://www.acl2013.org/site/accommodation.html.