SSRS Data Security Options?

Experts,

What are the different options available in SSRS 2008 for setting up Security to the DATABASES in a scenario where all data is housed / collecting into a single DB.

We need to allow limited access for the end users to view their OWN DATA.

In this scenario, am I limited to creating separate reporting folders and hard coding within each report to only allow end-uisers to see their own data?

I know the info above is a little scetchy, but the base question is, what are the different security options for SSRS 2008 in the case of us limiting access the same database for different Business Groups witin our company?

Thanks