Dear VR,
I cannot provide scans, and the Young Guard are hard to document, especially before 1812. There were many changes. However, the 1809 period is a bit easier, since there were not yet very many YG units. My uniform source is Funken, with some reservations. At this point, all members of the "grenadier corps" had uniforms based on the OG grenadiers, and likewise for the "chasseur corps."
1809 Young Guard Infantry units:
Conscrit Grenadiers
Conscrit Chasseurs
Tirailleur Grenadiers
Tirailleur Chasseurs
Conscrit Grenadiers:
Uniform like OG grenadiers, with the following exceptions: short tails on the jacket. White turnbacks piped red with red eagles. Blue shoulder straps with red piping, blue colar and lapels without piping. Shako with brass eagle badge, white side chevrons, red plume and cords. Funken shows short gaiters (to below the knee), but this might be incorrect, as the short gaiters did not appear otherwise until 1813. Of course, it's possible that the short gaiters originated with these units. I don't know.
Tirailleur Grenadiers:
Dark blue jacket with pointed blue lapels, piped white. Red turnbacks with white piping and white eagles. Red collar piped blue, red shoulder straps piped white, red pointed cuffs, piped white. Shako with white chevrons, brass eagle badge, white cords, red over white plume (Funken shows half and half). Again, Funken shows the short black gaiters, but those probably date to after 1812.
Note that all the grenadier corps below OG had white chevrons on their shakos. Not so with the chasseur corps.
Conscrit Chasseurs:
Blue jacket with blue pointed lapels, piped white. White waistcoat. Red collar piped white. Blue shoulder straps piped red. Red pointed cuffs piped white. Blue turnbacks with green horns and red piping. This may be in error. I would expect white piping along with the lapels, as well as red turnbacks, but I cannot be sure. Funken shows blue trousers, but I would expect white breeches with short black gaiters, based on Funken's other illustrations. Shako with white cords and green pompon.
Tirailleur Chasseurs:
As above, but green shoulder straps piped red, red collar piped blue, red turnbacks with white piping, green horn on outside turnback, green eagle on inside.