Data source and data set confusion

Maybe I am not understanding the way that these things work, but a little help would be apperciated.

I want to set up my shared data sources and "write them in stone". To be honest, once a data source has been set up, there should be no reason the change it unless a login credential changes, or we change the name of a database; changes to data sources should be done by a senior admin (like me!). All fine so far? Good...

Are data sets associated with/bound exclusively to the report, or the data source? For example, if I tie down my data sources and find a way to make them unchangeable, I then want myself and my collegues to be able to create/modify/delete data sets associated with the shared data source. If I do this, and then deploy my report (with overwrite datasources set to false) will they then work?

If the above is possible, is there a way that I can tie down the data sources so that only a select few can modify them? This would be a minimum requisit for a reporting manager (like me) where we have many developers creating reports and writing (and over-writing!) shared datasources - and causing a report completely unconnected with their current work to fail.

I realise that my experience is limited, and that SQL Reporting Services is young, but it is such a powerful product I can see it being used extensively across many industries in the future - mainly because it kicks Crystal in to touch on so many points.

OK, well, witha little experimentation, I have managed to answer part of my question. The data set is associated with the report, so setting the properties of the solution, over write data sources to false, I can create reports with custom data sets - no problems. Now for the tricky bit...

Does anyone have any as to how I can tie down the data source? It is accessible via Visual Studio, and the solution properties are easily changeable. Also, once these shared data sources are tied down, how does one add them to a solution? I can only find a way to add new data source, and then make it shared.

I have logged on to the reporting services area in SSMS and can see the security part, but how do I associate individuals to new roles in there? They will be domain roles, btw.

Thoughts/suggestions anyone?

sql