Hi Ari,
As Mark Kantrowitz stated, verify that the URL (Uniform or Universal Resource Locator) I heard these variations used interchangeably.
Again, thate URL Address should begin with https://
after verifying the prefix of the address. Look at the bottom status bar of your Internet Browser and verify that there is a Closed Pad Lock or a Solid Key.
If the Pad Lock is either NOT in the closed position or not present or if there is a Key but it's broken or there isn't a Solid Key visible either. As long as the site says https:// it is usually a proper authentic secure SSL site. Although I have heard of sites that don't have Pad Lock or Key appear in status bar but have https:// visible of having been and can be hacked.
Another think you can do is get a couple of security tools. One is McAfee Total Protection it comes with McAfee Site Advisor and PC Tools Browser Defender Toolbarch. Both of these products examine websites for threats and McAfee and Spyware Doctor with Anti-Virus, scan your computer for threats.
The one critical part of this is that you need to disable others, except for the one your going to run. And, Ad-Aware Personal Free is a good product too.
Frequent updates and Frequent scans are important; as new threats come out all the time.
So, again look for the https:// and feel secure, look for the locked pad lock or the Solid Key and feel reassured in your feeling of security.
Although, I would note that Helen Keller pointed out that Security it an illusion, and providing a false sense of safety.
I tend to agree with her.

Best Regards,
Douglas Uhlenhake

If the URL for the store begins with "https", as opposed to "http", it is a secure site. The 's' stands for SSL, the secure sockets layer that provides for encryption of traffic between your web browser and the web site.

Many web browsers will indicated that a web site is secure through a lock icon in the bottom of the web browser.

In addition to the issue of security, you may want to consider the use of a credit exclusively for online purchases. By doing so, you will find it much easier to stay on top of the cash flows for online purchases. Under no circumstances should you ever use a debit card for these transactions. The credit card companies will protect you against fraud. With a debit card, you are totally exposed.