The Internet and in particular the increasing availability of online documentation is significantly changing the way developers learn computer science topics, and programming ones in particular. Nowadays, developers have a plethora of resources available, ranging from online University courses and official programming manuals/documentation to video tutorials, screencasts, and discussions available on Question & Answer forums. With the aim of aiding researchers to better understand and leverage this large amount of resources and to better help developers, this paper empirically investigates the learning preferences and needs of developers related to the use of online resources. In particular, we conducted a survey with 205 participants, including computer science students and professional developers, which investigated their learning styles, information seeking behavior, preferred resources, and learning needs. The study results indicate a preference for combined visual and auditory learning, while indicating written tutorials and official documentation as one of the most popular resources used by developers. The study also indicated that, although online resources are considered valuable, there is need for better support for searching and browsing this kind of resources.