Search engines are becoming more important as the amount of available data increases. Information Retrieval (IR) studies the theoretical and practical issues of designing and building search engines. This course will expose students to the challenges and solutions of designing IR algorithms, evaluating them and building them. Some of the topics which will be presented are: Vector Space Model, Probabilistic IR, Web crawling, text processing, IR evaluation methods, Web search, IR-style search of structured and semi-structured data, personalized search, search in social networks and scalable implementations. The course will also cover advanced IR topics from research publications. By the end of this course students will be able to write algorithms to perform IR and search the web, as well as developing custom-made search engines.