As a student, you have free access to the Czech labour market without the need for a separate employment permit (up to the age of 26; source). However, the purpose of your stay as specified on your long-term visa or residence permit has to correspond to your actual activites. In other words, if you came here to study, your workload cannot affect your studies. Although there is no legal limit, we recommend our full-time students to work about 20 hours/week. Visit the Prague for all website for further information.
Probably the easiest way to find a job is to visit the biggest job portal in the Czech Republic: jobs.cz. One should also keep an eye on the job postings offered at the website of the respective faculty. Useful information regarding job opportunities in Prague is also available on the website of Study in Prague and Study in the Czech Republic. Further, various expats websites and Facebook groups are another useful source. If needed, our Carolina Centre also offers career counselling services in cooperation with the Centre for Integration of Foreigners.