RELIANCE, short for Research Lifecycle Management for Earth Science Communities and Copernicus users in EOSC, aims to realize the vision of FAIR research in EOSC by adopting a holistic research management approach based on three key and complementary technologies: i) Research objects (RO) as the overarching mechanism to manage scientific research activities, which relies upon ROHub platform as the reference service; ii) data cubes as the mechanisms enabling an efficient and scalable Earth Observation data access and discovery, which relies upon the Advanced geospatial Data Management (ADAM) platform as the reference service; iii) text mining and semantic enrichment services allowing to extract machine-readable metadata from RO resources, enabling researchers to discover scientific information at scale and to structure their own research, and which rely on the AI-based platform COGITO as base system. As part of the integration in EOSC, RELIANCE services will leverage and integrate with some of the EOSC core-cross cutting and added value services, playing a complementary role to what is already available and bridging between various EOSC services. RELIANCE will pilot the services in three different Earth Science communities, fostering the use of Copernicus data and demonstrating their efficacy in real-life vertical and multi-disciplinary scenarios, and will launch an Open Call to engage other communities. This document comprises the project management handbook. It contains all related information for running the RELIANCE project, including an introduction to the project and an overview of the rationale and the objectives. The main part of the document summarizes the information regarding the project management, structures and procedures, including some useful information from the Grant Agreement and its annexes, the Consortium Agreement and further decisions within the Consortium. RELIANCE partners will use this handbook as a reference manual during the implementation of their actions. The handbook will facilitate the management of the project, the monitoring of the overall progress and the communication between project partners and the Commission. Accordingly, it also provides the relevant information about the collaboration and communication tools, the organization and management of the meetings, and the timely and quality production of the planned deliverables.