The Print command prints the current file. The standard Windows Print dialog box will appear.
You can control what font is used for printing files with the File Type Options command. The File Type Options command lets you specify what font should be used for printing and what font should be used for the screen. Alternatively, you can tell Source Insight to emulate the screen font when printing. If you have a TrueType font selected, then emulating that font on the printer should work just fine. If you have a raster font selected, such as "MS San Serif" or "Courier", then printing that font on the printer may look blocky, or the printer driver may just substitute that font with something similar.
If you want to print your files with syntax formatting and color, you need to make sure you have enabled those options in the Page Setup dialog box.