People are going to want to know what's going on in the Sprint. A weekly demo works to allow outside but interested members to see and hear what's the current status.
To be maintained in JIRA - re-work underway for improvements. As contributions are accepted from community the Spring backlog needs to be updated.
The scope of the Scrum Team will include the community as they will help provide peer review of the design, implementation, testing, documentation, usability feedback etc. If needed, (and possible) the designation 'Core Scrum Team' and 'Extended Scrum Team' may be used.
Identify who's on the team and what is their primary function? Ensure the team understands the Backlog and what are the primary features that are to be coded. Note any vacations or upcoming holiday's that might be a factor during the Sprint.
Also, establish rules of engagement for the team ie: Every developer will ensure that code is unit tested before being checking in. ie: see Daily Scrum Meetings.
Daily Scrum Meetings
The Core Scrum Team need to synchronize frequently and the results of these interactions made public for the Extended Scrum Team. In the case of projects with full-time committers or commercial open source projects this should happen daily. In the case of solo or part-time core teams weekly or biweekly Scrums should be held. Scrum meetings can be held over instant messaging.
Establish the time and place for the daily Scrum meeting and if a dial in is required. The Scrum team is responsible for ensuring members are present. The ScrumMaster simply ensures the conversation stays focused and tracks and manages the blockers.
How To Contribute?
Burn Down Charts
Use a chart that shows progress throughout a Sprint and ensure it is transparent to the extended team.