The Third Microquasar Workshop (or the 'Fifth' Workshop on Galactic Relativ istic Jet Sources), was held in Granada, Andalucia (Spain) on 11-13 September 2000. The aim of this workshop in Granada, following the previous Microquasar Workshops in Greenbelt (1997) and Paris (1998) and the Workshops on galactic sources with relativistic jets in Jodrell Bank (1996) and Milton Keynes (1998), was to focus on the theoretical and observational aspects of microquasars. The study of microquasars, the sources in our Galaxy displaying powerful re lativistic jets, is a rapidly advancing field in astrophysics. The new instrumentation on ground (MERLIN, SCUBA, VLA, VLT) and aboard satellites (ASCA, BSAX, ISO, IXAE and RXTE) has provided important results, and much more is expected to come from Chandra and XMM-Newton. In the further future, powerful instru mentation will come online in the sub-mm (ALMA) and gamma-rays (INTEG RAL), extending our coverage to important regions for the study of microquasars. Energy transport via relativistic jets is one of the most important physical mechan isms taking place in compact objects. Large efforts have been devoted to properly understand the disk-jet connection, and even the effects of rotation or magnetic fields. Several new important advances have been made recently, both from the point of view of the theoretical treatment of jets and the different new observational tests.