I'm a cyclist, and I own an Android phone. I'm not comfortable with using one of those phone holsters on the handlebars (some of them are pretty flimsy, and vibration damage is an issue too), so I've been looking into creating a device which uses an Arduino board, a Bluetooth input, and a dot matrix LCD screen, with data input from a custom app on my phone.
I've got a lot of programming experience in lots of languages including Java, so I'm confident that I'll have no problems making the app on the phone, but I've never used an Arduino board before. In fact, I only really have a fairly basic grasp of electrical engineering. I'd appreciate some advice on where to start with all this.