We propose training possibilities in scientific computing and informatics at CERN. The LHC project with its global reach, size, longevity and enormous data acquisition rates creates new challenges in all domains of computing in the Organisation. As the same issues are beginning to appear also outside, in industry and society, it makes the training proposed both timely and appropriate. Early stage researchers will be closely supervised by experts using state-of-the-art, and sometimes unique, equipment. Particular emphasis will be placed on direct, laboratory-based training. Researchers will follow formal training courses in their specialized and related fields, and will be encouraged to attend a wide variety of other courses, colloquia and seminars. Work and training objectives will be clearly defined at the outset and regularly reviewed. The early stage trainees will be integrated in a multidisciplinary, international environment and will acquire transferable skills, which are highly valued also outside academia. CERN's facilities, training capacities and research potential are well above its current ability to fund researchers who would like to work in the Laboratory. The opportunities provided by the EST scheme will allow more young researchers to be hosted, and will extend the range of nationalities and disciplines that can be covered. Special efforts will be made to ensure appropriate framework conditions and equal opportunity policies, within CERN's well-established administrative infrastructures.