Vehicle tracking

Heey everyone,
Im about to start working on a new project, it's about using arduino somehow for that i can send informations to a database about my car for exemple. informations like, speed as a start, so Ummm any ideas would be helpful. thank you very much

Decide what tasks need to be performed.
figure out what type of sensors can be used to send/receive the needed data.
look into what sensors are available and how to integrate them into your hardware.
acquire some of said sensors and learn how to hook them up and use them.

decide how you will either save the data, or send it to whatever you will be using to data base the information.
acquire required hardware for data collection and learn how to use that.

figure how to integrate all the software pieces and implement that.
proto-type your subsystem and see if it works.
figure out why not and fix it.

You also need to define where the database etc. is - it is not clear from your post if this will be some sort of logger in the car that can track what it is doing or if it needs some sort of wireless connection to a server of some sort. The range will help determine if you need some sort of wifi, cell phone, or just what as the interface to your "tracking" connection. You also need to consider if it will need a continuous connection if you are talking remote or something that can buffer data and send it periodically when it gets a wifi/cellular connection etc. You will need to define just what your requirements are (do you need access to that data when you are not with the car?)