I've been engaging by some smaller companies recently and it has given me some insight into what the "best bang for buck" information security activities they should be doing. Here’s a list of some of the fundamental security controls they should consider.
1. Download a Business Continuity Plan (BCP) template from the web and back up your systems, put in mitigations for your critical systems that support your critical business processes.
2. Perform pre-employment screening and criminal background checks on new employees and subcontractors.
3. Require compliance with your security policy as part of new employment contracts and introduce a disciplinary process for non-compliance.
4. Download a copy of an ISO 27002 compliant security policy template from the web and customise it to your business.
5. Refresh job descriptions to include compliance with relevant aspects of the security policy.
6. Develop an information classification scheme (eg. a table with relevant examples of what is to be classified as what) and label the most important data in the company (eg. salary information, trade secrets, customer lists).
7. Develop an information asset handling procedure (ie. don't put HIGHLY CONFIDENTAL data on USB sticks and laptops).
8. Conduct security awareness training and require staff to acknowledge an acceptable use policy afterwards.
9. Ensure anti malware software is on all systems and centrally managed so it is always up to date and running.
10. Ensure all users are subject to email and web content management to stop the ingress of malware at the network border.
11. Ensure a firewall is in place, internet facing systems are in a De-Militarized Zone, outbound internet access is restricted to only through the web content management system and the firewall configuration is documented.
12. Ensure administrative and privileged accounts are not shared between staff and service accounts for applications are documented and have strong passwords set. Also avoid sharing of passwords for administrative accounts.
13. Implement identity management processes for user access provisioning, de-provisioning and regular review.
14. Implement a security incident management process.
15. Find out all of the free security features available in your applications, databases and operating systems - and configure them. You will be amazed what is possible with WSUS, Group Policy and Office's Information Rights Management in a typical Microsoft centric network environment.