Step 1: Drag files to a Media Bin from the Finder or import some of the built-in sources from the Import Media window.
Once loaded, click on a file to play it on the layer specified in the top-left of the media bin.
Step 2: Shift-Click on one or more clips to select them. Selected clips can be dragged to new locations in the bin.
Step 3: Right-Click on a clip and choose the 'Inspect Selected Files' option to preview and edit settings in the Workspace Inspector.
Also see this more detailed look at the File Inspector.
Step 4: To assign trigger shortcuts, inspect the Media Bin, click the 'Detect' button and then press a key on the keyboard.
Tip: Any available data-source can be used to trigger clips, besides keyboard presses, MIDI, OSC, DMX can be detected. Built-in providers such as audio analysis and LFOs can be assigned by the pop-up menu for each table row.