I presently have about 350,000 photos on external hard drives.

I am not familiar with the MAC programs but on my machine, which is running Windows 7, when I upload photos from the camera it opens a file and asks for a file name.

I insert a file name and it continues the upload, placing all the photos in that file, which is then located in "My Pictures".

To put a backup copy of the file on my external hard drive, I then connect the drive then hit Start & "MY PICTURES"

I simply locate the file in MY PICTURES, put the cursor on the file and right click, then hit copy.

On the left hand side of MY Pictures I locate the listing for the external drive (drive J). Put the cursor on that listing and hit paste and the upload to the hard drive starts instantly.

After it uploads if you want to double check to see if the file is on the external drive hit, START, then hit "COMPUTER" and it will drop a box showing all the storage devices for the computer.

Locate the external hard drive and put the cursor on the index, then right click and another box drops down, on the top of that box hit "OPEN" and it will drop down a list of all the files on the external hard drive.

I generally have about 300 to 500 photos in a file and it generally takes about 1 to 2 minutes to upload via USB.

You can also put photos on a CD by inserting a blank CD and when the box opens asking you want you want to do, hit "Open a Data CD", another box will open and ask for a CD name and it gives two options for how you want to store the files. Select format as a flash drive, and the CD can then be opened on any computer.

You can then go through the photos in MY Pictures and any one that you want on the CD you put the cursor on the thumbnail photo and right click the mouse. When the box opens hit "Send To:" then select the CD player.

From my DSLR I can get about 150 photos on a CD in JPEG or about 50 in RAW format.

Easiest way to be sure that it's reading from the backup file rather than the original file is go on your computer and rename the file. A simple change like renaming "Picture" to "Picture1". Then when you click on the file named "Picture" it won't try to open "Picture1".

A round of applause to you for wanting to check your backup! That's one of the big mistakes people make is to "assume".

Beyond that it's going to depend on how the backup is done. Sometimes backup programs will compress the data to save space. I usually prefer a straight copy rather than relying on a backup program.

Another good thing to do is check the data using a different machine. After all, in the event of a catastrophic loss, you'll be restoring or reading the data to/from a different machine so it's a good idea to see that you know how to access the data and that the data can be read and not risk what you suspect, that is that you're reading the original drive's data rather than the backup.

That method does back up your data and files but it does not back up any of the Operating system and updates etc. To have the most complete backup you should do a image/clone of your hard drive every so often that takes a snapshot of the entire hard drive including your Windows it would save everything exactly as it is and if you should need to do a recovery you just use that image/clone and it puts the pc back to the same state it was in. You just back the image up on your external hard drive as you do your pictures and files now.
there are now several good imaging programs that are free.
One of the best you can buy is Acronis True Image.

list of free ones.
disk imaging software

Partition Imaging and Cloning Software

Tutorial 1 - Install Acronis True Image

8 free software to image/backup/ghost your computer (free alternatives to Acronis True Image, Norton Ghost, etc.).

The problem with doing a full disk "image", "clone" or whatever term you like is that you need to put it onto an identical machine. I've gone through that before and you wind up spending more time adjusting for the different hardware than installing and tweaking from scratch. Plus, if you are using, for instance, Vista or XP, a new machine will likely have 7 on it giving the same issue. Plus, many new machines will be 64 bit where the old were most all 32 bit throwing another variable in the mix.

Although I do a full system backup once or twice a year (I don't have the same needs anymore as before), I concentrate on backing up the data that's important to me and like I said, the OS isn't a big deal. It'll take a lot of time in the event of catastrophic loss but adapting an image to a different system will be as time consuming I'd guess.

But each person's backup needs are different so you need to look at your priorities and choose a method compatible with your needs and time commitment.

It depends on what kind of backup you did. A full backup stores the entire working disk, in compressed format, onto the backup device.

If you are using backup software and a full backup exists, then a new backup may have been an "incremental" one by default. When an incremental backup is done, the only files written to the new backup set are any new files not in the old set and any files that have been changed. Ususally, this second incremental set is much smaller than the original.

Letrs suppose that the backup device has the following sets:

1. A full backup
2. Incremental 1
3. Incremental 2
4. Incremental 3

And now a disaster happens and there is a need to restore the files. The restoration has to follow the same order in which these sets were written. First, the full backup set is restored to the new drive followed by the incremental sets in order 2,3, and 4.

It is important that the sets were named in way to identify the order in which they were written. A common method is to include the date in the set name. Use either the ascending or descending format for the date, e.g. "day Month Year" or "year Month day"

I have big off-line disk and I do not use a compressed backup, nor do I backup my operating system. I back up only my data files and for that I do a direct copy. I have 2 hard drives in my computer and these are subdivided into several logical drives. I keep all my important files on one of the logical drives and when I backup, I merely copy the entire data drive. Its simple, easy, and lazy.

I suppose that if I were dilligent, I would keep an "image" copy of the system disk. That could save a lot of time in case of a crash, because several years of updates would be there. The problem is the system image must be current. There can be losses if an image was made and then actions were done that made changes to the registery such as an install of an update or software - and now a crash occurs. There is no record of the new registry. When the system is restored, the registry can not recognize the newly installed system files. In some cases, the system may lock up when the user tries to run one of the new programs.