There are different modeling perspectives. Which perspective do you want to model. In model driven development approach, model can be the base of code.

User perspective - managing device and its resources: messaging, voice communication, making use of sensors, managing files, managing data etc. Some domain-specific languages allow to create one model which is enough to generate the whole working application, I want to achieve something similar, although using UML.

Please take a look.

http://link.springer.com/chapter/10.1007%2F978-3-642-21470-7_15

http://reference.bitreactive.com/

http://reference.bitreactive.com/ is certainly good for any newbie to understand.

As per your requirement, I think for managing device and its resources, MARTE would be suitable UML profile.

You can more information at - http://en.wikipedia.org/wiki/MARTE

Thank you for your valuable answers.

One more question - which Eclipse plugin would you recommend to create models in UML (class and sequence diagrams)?

I have tried Papyrus, although it is terrible - most of time is spent on fighting with it's interface and UML vision, not on modeling a solution.