Cloud Computing builds on the latest achievements of diverse research areas, such as Grid Computing, Service-oriented computing, business process modeling and virtualization. As this new computing paradigm was mostly lead by companies, several proprietary systems arisen. Recently, alongside these commercial systems, several smaller-scale privately owned systems are maintained and developed. In this paper we present our research results performed within the S-Cube European FP7 NoE project to enable automated service provisioning for users on a highly dynamic infrastructure consisting of multiple Cloud providers. We developed a Federated Cloud Management architecture that provides unified access to a federated Cloud that aggregates multiple heterogeneous IaaS Cloud providers in a transparent manner. We have also incorporated an integrated monitoring approach that enables more reliable provider selection in these heterogeneous environments.