If you are currently working with a reference management system and want to switch to EndNote it is no problem to take your references with you.
If you are switching from Reference Manager to EndNote, this video will show you how to do it: http://www.youtube.com/watch?v=IcIKlnUPhwY&list=PL32C57F72E59A685D&index=2
How to export references from Zotero and then import them into EndNote is shown in this video: http://www.youtube.com/watch?v=6FkJW66ODws&list=PL32C57F72E59A685D&index=13
Switch from Mendeley to EndNote is shown in these pictures: http://endnote.com/sites/en/files/media/basic/mendeley2endnote.pdf
And if you have a set of references in a spreadsheet or database program, here’s how to get them into EndNote: http://www.youtube.com/watch?v=28XuGsjiIoI&list=PL32C57F72E59A685D&index=4