Tripod, RAW, and ISO100 will be a good start.
Use the timer or a remote and mirror lock up for the best results. And mirror lock up + self timer will get you more shots faster! The self timer is only 2 secs delay when you use lock up as opposed to a 10 sec delay on my 30D.
I would tend to use Av or Manual mode, set the aperture first and then stop up and down the shutter speed for the right effect.
Try some nice long exposures to capture light trails from traffic/trams/ferris wheels.
Keep your wits about you too! Have fun