To roll up your data, follow the link in the Web Part to open the tool pane, or click the drop down arrow in the web part and choose Modify Shared Web Part.
In the tool pane choose whether you would like to roll up from a single site collection or multiple site collections.
Choose either which sites you would like to aggregate from or tick each site collection you would like to aggregate from.
In the tool pane choose either the list type or the content type e.g. Tasks (List Type) or List (Content Type)
If you are aggregating from Content Type you can also select Child Content Types.
Choose from one of three views (SPGridView) is recommended for non-XSL developers.
Using the SPGridView click the cog image next to the Grid View option.
Another toolpane will appear on the left hand side of the page allowing you to select the columns from your desired list.
Click ok to save your settings.