Hi ghostbusters.
A good idea for DIY project.
You want to start with thinking what you want to do on the bike and break it down into sections.
Say left and right blinkers, brake light, speed sensor, travel distance per trip, day, week and total.
Ability to send data to your computer via WIFI or GSM.
Bike theft alarm and tracker.
The possibilities are endless.
For the small distance covered over your bike, wireless may be a bit of an overkill and may be prone to interference and woukd constitute a large portion of power to use with the micro.
Running everything from one power source is the easy way and since you will need wires for this, wires to the lights is easy.
A small battery being charged by a bike generator (use to have them running on the wheels to run a 6 volt headlight globe when i was a kid) would probably not need external charging from another power source.
With a small oled display on the handle bars could be good. Every kid on the block will want one.
Daz