Virginia Tech's site license for EndNote has been renewed until May 2020. This means that current users of EndNote can continue to use the software without interruption, and new users of EndNote can download the software knowing that it will be available until at least 2020.
The basic unit is an EndNote library. You can create entries manually by typing bibliographic information (e.g., article title, author, journal name, volume, issue, pages, URL, etc.) for each new entry or copying and pasting from an email message or online citation. These entries can be searched and organized, and can be imported into word processing programs like Word as inline references or bibliographies. There, EndNote will assist with the proper formatting of those citations, using styles like APA or MLA, among hundreds of options.
You can also populate a library is through the use of an import filter to translate saved text files into the proper bibliographic format. Typically, you would search a database, mark or indicate which records you want to export, then save those records as a .RIS file (or whatever option that database allows). Then you would import those citations into EndNote (often you will be prompted to import as soon as the file downloads from the database). EndNote comes with hundreds of import filters. The latest files for numerous databases can be downloaded from the EndNote web site.
Another way to populate an EndNote library is to directly access and search a database on a Z39.50 server using a connection file. Search results will appear directly into an EndNote library. This is a popular method because it is simple. Unfortunately, almost none of the connection files for commercial databases work for off-campus users, and they offer less sophisticated searching options compared to what is available through a database's native search interface. Persons connecting from off-campus through the VPN using connection option #2 (route all traffic through the VPN) are recognized as being on-campus, so connection files to commercial databases will work. EndNote comes with hundreds of connection files. The latest files can be downloaded from the EndNote web site.