Many quantum communication schemes rely on the resource of entanglement. For example , quantum teleportation is the transfer of arbitrary quantum states through a classical communication channel using shared entanglement. Entan-glement, however, is in gener al not easy to produce. The bottom line of this thesis is that a particular kind of entanglement, namely that based on continu-ous quantum variables, can be created relatively easily. Only squeezers and beam splitters are required to entangle arbitrarily many electromagnetic modes. In the first two chapters of the thesis, some basics of quantum optics and quantum information theory are presented. These results are then needed in chapter III, where we characterize continuous-variable entanglement and show how to make it. The members of a family of multi-mode states are found to be truly multi-party entangled with respect to all their modes. These states also violate multi-party inequalities imposed by local realism, as we demonstrate for some members of the family. Various quantum communication protocols based on the continuous-variable entangled states are discussed and developed in chapter IV. These include the teleportation of entanglement ( entanglement swapping) as a test for genuine quantum teleportation. It is shown how to optimize the performance of continuous-variable entanglement swapping. We highlight the similarities and differences between cont inuous-variable entanglement swapping and entanglement swapping with discrete variables. For this purpose, we examine the infinite-dimensional limit of the latter. Chapter IV also contains a review of quantum cryptographic schemes based on continuous variables. Finally, in chapter V, we consider a multi-party generalization of quantum teleportation. T his so-called telecloning means that arbitrary quantum states are transferred not only to a single receiver, but to several. However, due to the quantum mechanical no-cloning theorem, arbitrary quantum states cannot be perfectly copied. We present a protocol that enables telecloning of arbitrary co-herent states with the optimal quality allowed by quantum theory. The entangled states needed in this scheme are again producible with squeezed light and beam splitters. Although the telecloning scheme may also be used for "local" cloning of coherent states, we show that cloning coherent states locally can be achieved in an optimal fashion without entanglement. It only requires a phase-insensitive amplifier and beam splitters.