Instead of saving from Lightroom, the terminology used is "Exporting." By exporting your files, the original is preserved, and you are creating a final version of the file, in whatever file format is required for its intended use.
You can export one or many files from Lightroom by making a selection and choosing "Export..." from the file menu or from the right click menu. You can also click the large "Export..." button at the bottom of the left side panel in the Develop module, or use the keyboard shortcut Ctrl-Shift-E. However, it is not necessary that you export your edited photos until you need to use them somewhere else--to send to a printer, post online, or work with in another application.
When you do export your photos, Lightroom offers a number of options for the exported file, including format, output location, file name, size, sharpening, watermarking, and so on. If you often export files using the same criteria, you can save the settings as an Export Preset by clicking the "Add" button in the Export dialog box.