You could use one of the following Data Backup Devices to do  your backup on a daily, weekly, and monthly basis.

The devices for back up are:

• Tape Drives

• CD Rom (rewriteable disks)
  

• Flash drive
  

• External hard drive.

• NAS (Network Attached Storage)
  

Each of these Data Backup Devices has pros and cons for backup. I will list them here:

Tape Drives:
Pros: Large capacity, can be encrypted, fairly long life.
Cons: Expensive, both the Tape Drives and the media. Complicated.

CD ROM or DVD:
Pros: Medium to large capacity, extremely long life, easy to store, can be encrypted.
Cons: Complicated procedure, read only once the data is written.

Flash drive:
Pros: Cheap, small, easy to use. Can be encrypted.
Cons: Low capacity, easy to lose or to steal, easy to erase!

External hard drive:
Pros: Large capacity, easy to use, can be fairly small, medium price. Can be encrypted.
Cons: Easy to steal.

NAS - Network Attached Storage as back up storage are becoming the most popular.

Pros: Large capacity, this could be a workstation that has the hard drive or volumes shared for access by network users or a third party device.

Cons: If you use a Windows Operating System such as Windows 2000, XP, or Windows 7 for the NAS then only 10 connections are allowed at time. Cheaper than a full Server. 

Scheduling:

You should review how much data you generate daily, weekly, and monthly. If you can back up your data at the end of each business day the better it will be when you need to recover your data after a catastrophic event. There are different ways to backup your data.

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You go to each folder/directory and copy all the contents to your backup media. Or you could use a batch file to do the copy, this would be a little more tedious, it makes restoring a single file easier.

Automated:

You use a program to search your computer(s) for any document that has changed during the given period. You can set the program to do daily, weekly, monthly, or full backups of selected folders/directories and select the file type to backup. You don't need to backup programs or their associated files. This type of backup will be discussed in the next section.

You may want to read this before choosing your back up media...