SSRS

A frequently asked question is what the SSRS infrastructure looks like in SharePoint integrated mode. Well, like this:

• On the clients: rich clients optionally leverage the ReportViewer Windows Forms control, ASP.NET pages use the ASP.NET ReportViewer Web control.
• On each SharePoint WFE, you need to install the Reporting Services add-in. Every WFE also contains a report viewer web part, reporting pages to manage SSRS, and a proxy that communicates with the report server.
• On the middle-tier: SSRS can run as a true middle-tier application that doesn't have to (but can) be hosted on a WFE. The middle tier contains the report server itself.

        Data tier: the report catalog, report data, report server config files and registry, entries in the SharePoint config database, reports stored in the SharePoint content database.

        In other words, in production you do need to be able to access reports in a reports library,

        None of the above options. If you'd take a look at the SharePoint 2010 Administration's Companion by MS Press, it contains a truly awesome chapter about SSRS and PPS 
        (just bragging, 'cause I wrote it myself :-), and it clarifies the point:

• On the clients: rich clients optionally leverage the ReportViewer Windows Forms control, ASP.NET pages use the ASP.NET ReportViewer Web control.
• On each SharePoint WFE, you need to install the Reporting Services add-in. Every WFE also contains a report viewer web part, reporting pages to manage SSRS, and a proxy that communicates with the report server.
• On the middle-tier: SSRS can run as a true middle-tier application that doesn't have to (but can) be hosted on a WFE. The middle tier contains the report server itself.
• Data tier: the report catalog, report data, report server config files and registry, entries in the SharePoint config database, reports stored in the SharePoint content database.

Further details can be found in the SharePoint 2010 Administration's Companion by MS Press.