I'm new to github and I like to help other people with his projects that I find interesting. I know there's a lot of guides in the github place, but I think it could be nice to gather a bunch of real people's experiences.
So, I invite you to post about your first experiences in github. Whether you are a not-so-newbie or you are a heavy rock in github comunnity, I think your lines could encourage real newbies like me about entering this great open source community.
Github is just a website which aggregates projects. You need to ask the project maintainers themselves how they want you to help. It is pointless asking here as we do not know the specific rules for the project you are interested in. Different projects have different ways of doing things and require help in different areas.
Learn how to use Git would be the number one thing to say. Oh, and make sure you following the coding standards.
It's pretty simple. You can summarise a simple community project's development into a circular process of just two simple actions:
Bug tracking. Testing the software, logging bugs, making sure they're filed in the right place, asking for more detail, etc. If valid, these reports carry the detail for the next phase:
Patching. Target a bug, reproduce it, change your code to fix it, test locally and push your patch. This loops back around to the first phase where the bug report is marked fixed or otherwise.
You've got to start with phase one. You don't have to follow a bug right through and you can help as simply as just hopping in and making sure other bug reporters are doing the right things (making sure there are dumps where applicable, making sure the tags are right, merging duplicates).
Or you can be more involved and test the software to find new bugs. The onus on getting things right is now your own.
Once you're more familiar with the project, its code and its maintainers, then you might be ready to get involved with fixing some of the outstanding bugs.
An important thing to remember is you can ask for help. Nobody expects an outsider to understand all the code or be able to fix all the bugs. Maintainers will very often be more than happy to help somebody get started because they'll often get their time back from work you do on the project.