This is when it finally clicked in for me....we use 'les' and 'des' in french to showcase something is plural which makes more sense when actually speaking french due to most french words sound the exact same when spoken...example: robe et robes they sound the exact same in french but in contrast with proper french grammar: la robe et les robes..it is easy to identify the plural...J'adore le français
roue is more like roup (as in soup) without the p, but a bit "longer"
rue is more difficult for English speakers - lips are tighter and a bit broader. depending on how you pronounce "ew' it can be a bit similar to that.
Have a look at Green tea Girls links in this thread.
Also - Ms Lawless has lots of sound bites on this one
Lastly, just for fun, have a look at this one - it should help cement the pronunciation :)