* Long hood, short deck: The proportions emphasize the powerful engine.
* Hidden Headlights: Retractable headlights are a signature element, giving it a sleek profile when off.
* Fastback roofline: The roof slopes dramatically down to the short rear deck.
* Large, prominent grille: The grille is usually quite wide and imposing.
* Wide stance: The Charger sits low to the ground with a broad track.
* Taillights: The taillights are typically horizontal and span the width of the rear.
The exact appearance will vary depending on the trim level (base, R/T, Daytona) and any modifications made over the years. R/T models, for example, had more aggressive styling cues. Color also varies greatly; you'll find pictures in a wide range of colors from subdued pastels to vibrant muscle car shades.
To see what one looks like, I recommend searching "1969 Dodge Charger" on Google Images or a similar image search engine. You'll find plenty of pictures showing the various styles and colors.