Cyberduck is a very user friendly SFTP/FTP client that focuses a lot on big icons, drag and drop and nice status icons. You can save multiple hosts, so you can easily change between your servers.
FileZilla is another program I simply would have a very hard time living without. It’s simply the one of the BEST FTP/SFTP clients ever, mostly because it works on Windows, Mac OS and Linux.
I use it for my company projects and as a standard practise for my students as a teacher. It’s an open source project, which makes it a very available tool. FTP and SFTP/SCP are quite essential for transferring and publishing in the web development world.