[Porsche-O-Phile]

I did this for a long time when I lived in Chicago - it's fun, rewarding and you'll greatly enjoy it.

First, make sure the bike is as indestructable as you can make it. I used an old-school early Peugeot mountain frame (still have it too) - all steel, probably weighs 40 pounds. It's a beast. A tank. But that's what you want.

Second, any "breakaways" you have for the seat posts, wheels, etc. REMOVE THEM. Either that, or count on using them every single time you park the bike, even if it's for a two-minute cup of coffee. If not, the "quick release" will become an invite for theft. Use actual nuts and bolts (and carry the appropriately-sized tools with you).

Third, Use slicks. Mountain tires are good for trails but are going to suck on roads & bike paths. You'll burn a lot of extra energy to get nothing out of it.

Fourth, as far as lighting goes, the helmet idea is good but you can also get the little LED (Cats Eye) devices that mount to the handlebars (front) or seat post (rear). They're very good and the batteries last a long time since they use LEDs. If you're doing a fair amount of street riding (I did) I actually used two of them on the rear under the seat post set to "random flash". Anything you can do to make the idiots see you is a good thing.

Next, I'd invest in a reflective vest (the orange, construction worker mesh type). They weigh nothing, can be folded up to take next to no space, and will help a lot with your visibility at night.

Good helmet and gloves - duh.

You should always carry a full set of tools (shouldn't be all THAT many, but the wrenches, allen wrenches, screwdrivers and such that fit the connectors on your bike). An air pump, dial gauge, spare tube, etc. are all good ideas. Ditto on some bike lube. Sounds like a lot but really isn't.

I stronly recommend getting a good set of panniers and/or a rack. Way better than a backpack and keeps the center of gravity lower. The fenders are a great idea too.

Obviously park in a well-lit spot with a lot of foot traffic and get the biggest most obnoxious honkin' lock you can stand. The kryptonite U-locks have been shown to be ineffective since they can be opened with a ball-point pen case (supposedly they've re-designed them) but a simple BIG hardened-steel chain (you can put a plastic sleeve on it if you want) with a nice big padlock on it works well. Ditto on the 1/2" thick steel cable deals (that's what I use). People will steal the stink off of **** given half the chance. Never doubt that they'd make off with your bike. I've known plenty of people it happened to and I actually lost a front wheel 'cause I was too lazy to run the lock up to it. Word to the wise. . .

Have fun.