Questions about data formats for integration with software Options

[mikedin]

Hi, all!

Several days ago we have started a new weather service. The main idea is mix user data and data from weather stations for getting global weather map.
We solved users part of task and, now we try to integrate weather stations.

We have an API in early beta stage, but have no information about weather station data formats and methods of integration of software and stations. So I have an questions:
1) Is there unified format of weather data that we can use?
2) How much differ output methods for different weather stations? As example, I know that some stations produce files with strings on one "sample"... is it ommon method or other stations has API for getting data?
3) What types of data is produced by weather stations? Can you choose common types? Temperature, Humidity, Wind data... that else? That of this data have major importance?

And, sure, if anybody want to help us with API testing or develop, you are welcome!

Regards,
Mikhail Samokhvalov.