Decide how much memory you need in an external hard drive

If you plan on storing large files or you have a lot of data, consider a 120 GB external hard drive or larger. The amount of storage for the price is increasing, which is good news for businesses and consumers. If you don't need a lot of memory, you may find that a 100 GB external hard drive or less will fit your needs perfectly.

I recommend: Buy.com offers a wide range of external hard drives, including those by top manufacturers like LaCie, Western Digital and Maxtor. You’ll also get free shipping on most units.

Consider whether you need a portable USB external hard drive

Flash drives or portable hard drives can be great for back ups on the road or for transferring files from your work to your home computer. However, the amount of memory is generally less with portable hard drives. Keep in mind that you can always use both a regular external hard drive and a portable one.

I recommend: Iomega has several portable hard drives available with a range of memory capabilities. Try one of SanDisk’s portable flash drives for easy portability.

Pay attention to external hard drive reviews

You need a reliable system that will keep your files safe and accessible. Although any computer component can fail, some external hard drives have an infamous reputation for this problem. Check out the many online reviews and guides for external hard drives to make sure you're getting a reliable system.

I recommend: Compare external hard drives with PC Magazine’s easy chart. Check the reviews on CNet for the particular external hard drives you are interested in.

Investigate the software that comes with the external hard drive

The included software can make file transfers a piece of cake or a frustratingly long process. Look for software that you can customize to do automatic back ups or that will transfer files with a single click.

I recommend: LaCie has a "1-click" back up solution for their external hard drives. The software enables you to easily configure the transfer to particular folders or targets. Protect your external hard drive with StorageCrypt encryption.