There are many ways to select things in Blender:
- RMB: Select object
- Shift-RMB: Multi-select objects
- B-key: Box select
- B-key (twice): Paint select
- Ctrl-LMB drag: Lasso select
The Outliner window
The Outliner window is simply another type of window that can be added to the Blender interface via the Window Type dropdown menu. This menu can be found at the leftmost position on the Header Bar of any window type.
In your Outliner window, be sure to go to the View menu and select Outliner. Depending on your defaults, you may be viewing the OOP Schematic (the thing with the boxes and wires).
Selecting objects in the Outliner causes them to be selected in the 3D View as well, and vice versa.
There's a search feature in the Outliner that's very helpful when your scenes contain many objects. Also notice the icons in the Outliner, next to each item. These help you to control an object's visibility in the 3D View, selectability in the 3D View, and renderability. They also have helpful tooltips in case you forget.
In the 3D View, you can also select objects based on their relationship to other objects. Use the Shift-G keystroke to see the Group Selection options. This works in both the Object and Edit modes. In Edit mode, be sure to check out the different selection options available based on the current selection mode (Vertex, Edge, or Face selection mode). You can switch between the selection modes using the Ctrl-Tab keystroke.
And, another selection tip that really comes in handy is to use Alt-RMB. This will display a menu of objects that are currently underneath the mousepointer. This is helpful when many objects are overlapping or for objects that are occluded by other objects. Be aware that this popup menu will not appear if there aren't any overlapping objects to choose.