I believe that QGIS still comes with gdal2xyz.py and using this you can convert your raster to a text file.
Open a terminal in the directory containing the raster and run:
gdal2xyz.py filename.tif filename.txt
The text file will contain space-delimited xyz triplets comprising an x ordinate, a y ordinate and a z value (from the raster).
You will need to add a new first line to the file, something like "x y z" (without the quotation marks). Having done this you will be able to load the file into QGIS using the "add delimited text" tool, selecting "space" as a delimiter.
In QGIS you can then style the points: Properties -> Style Tab -> Categorized and then use font symbols to style the points.