some good info in here. I'll add a few tips for getting up buildings, since that's a particularly interesting topic for me (for some reason).
Ascending Fire-escapes : hold down your right-mouse button to steer (assuming you haven't rebound it). You can rip up a fire-escape in no time (or a stair-case, whatever) by steering with your mouse and not the keyboard. Actually, steer with your mouse most of the time and you'll find you have much, much more control than with the keyboard.
By-passing fire-escapes. With absolutely no jump enhancements or powers, one can leap up the side of a good number of the buildings, especially the ol' brick "apartment" buildings with relative ease. This may be a bit tricky to explain but with a little practice, it's easy as pie.
First you have to be at a building that actually has a bottom edge you can jump to, that should be a given.
Run at the side of the building from an angle, leap up while still moving and you should land on an edge. Keep the space-bar depressed and continue to "run" at the building at an angle. You should find yourself jumping up and to the side, catching an edge on the next level up.
As you approach the side of the building, switch your angle of incident (that means angle yourself towards the other side of the wall you're going up) and you should switch directions while still maintaining upward movement (or you'll go sailing off of the side of the building since you didn't change directions early enough). Continue to do this, zig-zagging your way up the side of the building until you reach the top.
Note to Superspeeders, you can do this REALLY fast, BUT if you don't let-off as you crest the top of the wall, you'll totally over-jump the roof and go right over the far-side of the building.
Other handy-tips:
Click the arrow on the team-window. It will roll-out additional info about your teammates. It will tell you where a teammate is when they are in a different zone and what buffs they have when they are in the same zone.
Simply click a teammates name in the team window to select them (and set them as a waypoint.

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/bind , "nop" to clear that damn default "/tell $target" key. I always seem to hit this at the most in-opportune times. The syntax
/bind <key> "nop" will clear a bind for whatever key you specify.
Right-click a teammate (or their name in the team window) and select "Info" to see exactly what powers that person has. Don't waste time by asking teammates to stop and tell you what they can do.
A good pull is when the monster comes far enough from his group that the rest of his buddies can't see or hear him counter-attack. Too often I see a really good pull get nixed because the team doesn't back off far enough to get the target out of range of his friends. Once the rest of the group sees their minion buddy open fire on something, they all wake up and attack too.