For a Mac--make sure to use iPhoto! The program has improved tremendously throughout the years. iPhoto also has some photo editing features within it. I feel it's strongest feature is it's organization.
When you plug your camera in it will ask if you want the photos to go into iPhoto. Say "yes" and it will automatically do this each time you plug your camera in.
Photos: they will load and be grouped (Events) by date. You can later on merge the dates if you choose.
You will have a library of "Events," "Photos," "Faces," and "Places". You can adjust these within each library. To delete a photo from your photos completely:
Within "Photos" - click the photo/press delete, then: Menu Bar: iPhoto: scroll to "Empty Trash". This will permanently delete photos. ***This is the only program on a Mac that has it's own trash can, so it has to be emptied separately.
If you have a chance play around within iPhoto. You can easily create a slideshow/music-using iTunes.
Have fun!