I prefer HasT's second solution if there are more than a handful of points. Enter coordinates (separate X and Y columns), labels and any other data in your spreadsheet of choice. Save in CSV format and use "Add Delimited Text Layer" to add in your points as a layer:

and a window comes up asking you which columns to use as X & Y coordinates and other options.
Edited to add: see also this tutorial linked at the QGIS Wiki.