This is a list of the recommended resources for small business, IT security, and home users.  We have tested most of these tools personally and found they get the job done with the least amount of frustration and cost.

We will keep this list updated as we discover new and useful tools.

Free Antivirus Software
Avast
Avira
AVG
We have personally used AVG and found it well worth the price. If you will not be doing any risky surfing it works well. However, the definition updates seriously slow your system’s performance so they should be scheduled for when your not busy.
We wrote a post comparing all three and you can see it HERE.

If you are a Windows user then you can try Microsoft Security Essentials.

Paid Antivirus Software
Kaspersky
NOD32
We personally recommend Kaspersky which is dang near bullet proof. If you will be doing hardcore surfing it is the AV software of choice.
If you want light fast software that is effective as well try NOD32.

Free Antispyware Software
SUPERantispyware
It takes awhile to run a scan but it works great.

Free Intrusion Detection System (IDS)
Snort

Free Network Mapping /Enumeration
NMAP
This handy piece of software comes has a helpful Graphic User Interface called ZenMap.  The GUI provides tabs, pull down menus, and fields that allow you to thoroughly explore a network. We have used it for  port scanning websites quickly and it works like a charm.  Additionally, users can discover what applications, operating systems, firewalls, versions and other system characteristics are running on a network.

Security Tool for MACs
Lil’ Snitch
This is my favorite security tool for my PowerBook. It is a network monitor that detects when another system is trying to connect to your computer’s ports and allows you to block the attempt.

We have tried some of the other security tools designed for Apple such as the antivirus software ClamXav and Nortons for MAC and decided against them.  Nortons bogged down our system too much and ClamXav was not refined enough.  Anyway, Lil’ Snitch is free if you dont mind a popup reminder every three hours.

Free Shopping Cart Software
ZenCart
For security reason we prefer a paid shopping cart like on the the ones below because of the active ongoing development. However ZenCart has a large developer community and was based off the godfather of opensource software OSCommerce, so security updates can be rolled out fairly fast.

Paid Shopping Cart Software
1ShoppingCart
E-Junkie
We prefer 1ShoppingCart for a full featured shopping cart and eJunky for lighter tasks such digital delivery and affiliate sales.

Merchant Account
PowerPay

Gateway
Authorize.net