What's shutter mode? Are you talking about the mode for exposure (manual, shutter priority...)? If that's the case, depends on your camera, I think I remember you saying, just can't remember right now.
I usually always shoot manual with autofocus though, for anything (save some close ups where I'll do manualfocus). I think I may switch to Aperture Priority cause all I need to do is spin the dial, and it's harder to press buttons with gloves on (can get cold in Edmonton) so yeah. Any mode will probably do, it's just which one works best for you, and that's something you need to figure out on your own.
One thing is try not to be shy of taking photos head on of the sidewalk with pedestrians and whatnot. It can be a little nervous and odd to do at first round, but try not to be shy cause you'll get some good shots.
Don't be afraid to lie on your back or tummy, crouch awkwardly to frame things properly.
Don't worry about what people think of you taking pictures of them or whatever, just focus on great pics.
Try to do interesting angles. Play around with the viewfinder and try different angles for buildings, etc.
Wide angle shots are really great if you're trying to capture a big subject, like say a whole urban park, or a row of buildings...
Try to look for interesting elements. If you see something that makes you think "hey, this looks quite cool" or "this is interesting", even if it seems trivial, like some bike racks or something, photograph it, photograph everything. Cause you never know what will look good in-computer.
Don't use flash! Things tend to look awkward I find when you use flash for street shots.
Don't just go for the business district or the well known areas, go to areas rarely photographed (or at least well...) and offbeat places!
And, good luck! Hope to see the thread soonish.