I know ther's stats out there somewhere for the arrows you light and fire (like in Robin Hood Prince of Thieves & Gladiator). I just suddenly drew a blank. Anyone want to give me a hint?
Magic arrows with the flaming property are in the DMG.
Regular arrows ... not in the core rules but certainly in d20 supplements (eg, alchemist's arrows in the A&EG).
As a house rule kludge, you could rule that pre-prepared arrows (wrapped in cloth soaked in oil) could function as alchemist's arrows (similar to the rules for oil/alchemist's fire):
Flaming arrows take a full round to light and prepare to fire. One round after impact, the flaming arrow ignites the target and causes an additional 1d4 points of fire damage. The target may attempt to put out the flaming arrow before it ignites him, by taking a full-round action and making a Reflex save (DC 15). Rolling on the ground adds a +2 to the save.