This paper briefly describes both organizational and technical issues and approaches involved in creating an operational digital library at the University of Crete, found at http://dlib.libh.uoc.gr. We investigate and describe our approaches and experiences, the last few years, on setting in operation a Digital Library with many collections. We had to analyze the library goals and user needs, to select appropriate software, to make flexible design for the additional functionality needed, to adapt and extend the selected software to make it applicable to the current demands, to install and configure the software, to improve it using feedback, and to interact with document authors and librarians to make the digital library friendly, usable and easily maintainable, and even to collect and digitize the library material. The final system is operated by current library personnel. The main technical issues are related to the design, implementation and application of features of digital libraries, such as multilingual storage and interface, generalization of the software to permit searching on heterogeneous collections, adding support for the Z39.50 protocol and tools that simplify the configuration, administration and data insertion to the digital library, as well as tools to input or modify the metadata and to upload data, when submitting new documents in the digital library.