Data Source, Dataset, Data Region
I answer these questions in this video tutorial. I show you the basics of what you need to know to get a grid of data up on a report. As well, I cover the bones of all SSRS reports – a Data Source, s Dataset, and a Data Region.

These are the three things you must create when you develop an SSRS report. They answer the three fundamental questions need for a report.

1. Where are you going to get the data? - A Data Source
2. What is the data you need? - A Dataset
3. How do you want to display the data? - A Data Region

I also cover creating and publishing the port to the Report Manager Website. This tutorial covers all the fundamental pieces you will use to create standard SSRS tabular reports. Please ask any questions you may have.
Best wishes and good luck!