[Wine] Want to contribute but how?

[fenistil]

Hi all,
I am quite new to Wine but I think this project is really worth the trouble and energy I am willing to put into it's dev.
So I have a specific application that runs on Wine but not stable. There are cases when it fails. This is an app that uses 3D (DirectX) and I'd love to improve it's playability under linux. I am hoping that I can somehow provide information for the devs so that they can look into it.
So the question is, how do you debug Wine on a specific application and how can you determine where the problem arose and things like that?

All help is appreciated... 
Regrads,
Fen