for the sun u have some options

use a directional for the sun as this will cast all the shadows parrallel

or u could use an array of spot lights however u may find that the shadows converge

wen doin daylight u need light from the sun
skylight - so shadows r not 100% black
bounce lights - lights placed inside buildings

u may not need all of these though

jemery birn digital light and rendering is the best book on lighting

u could use a ambient for the candle an light link it so u can use other light to better illuminate the scene

good luck