The main communication tool we use is a mailing list:
Feel free to ask any kind of questions but always prepend your email subject with "[meta-raspberrypi]". This is because we use the 'yocto' mailing list and not a perticular 'meta-raspberrypi' mailing list.
All the contributions should be compliant with the openembedded patch guidelines: http://www.openembedded.org/wiki/Commit_Patch_Message_Guidelines
To contribute to this project you should send pull requests to the github mirror (https://github.com/agherzan/meta-raspberrypi). Additionally you can send the patches for review to the above specified mailing list.
When creating patches for the mailing list, please use something like:
git format-patch -s --subject-prefix='meta-raspberrypi][PATCH' origin
When sending patches to the mailing list, please use something like:
git send-email --to yocto@yoctoproject.org <generated patch>
In order to manage and trace the meta-raspberrypi issues, we use github issues: https://github.com/agherzan/meta-raspberrypi/issues
If you push patches which have a github issue associated, please provide the issue number in the commit log just before "Signed-off-by" line(s). Example line for a bug: [Issue #13]