Security Suite Avira AntiVir

Yes, you need to protect your business with a solid antivirus package, but big-name, enterprise-level protection can be really expensive. At its most basic, Avira offers security for individual PCs for free (if you're willing to deal with one ad pop-up per day); but if you need protection for file and mail servers or other central services, Avira can provide such tools as well, for a generally reasonable price. (pricing varies by protection level)

Social Networking LinkedIn

When it comes to finding employees, contractors, service providers, and even outsourcing partners, LinkedIn has proven to be an invaluable tool for many businesses. But the real beauty of LinkedIn is something that becomes apparent only with use and time: As you expand your network--recommending other businesses, and otherwise participating--you may find that other LinkedIn users are recommending your business, as well. In addition, a Q&A system lets you ask for general advice on all matters business. (free, up to $50 per month for premium services)

Task Manager Chandler

Post-it notes and day planners are so 1988. Get your schedule, brainstorming notes, to-do lists, and just about anything else you have tacked up around your office into one place--your PC, that is--with Chandler. This free, open-source application gives you deep control over your day while still being easy enough to use that you'll never have to crack the manual. (free)

VoIP Skype for Business

Spend megabucks on your own PBX (private branch exchange), or spend nothing for a voice-over-IP setup like Skype for Business? If you're on a shoestring, the answer is clear. Sure, Skype can't easily handle things if, say, you want to run a tech support call center out of your basement. But for modest calling needs-especially if you place a lot of international calls-Skype is a solid and hugely affordable choice. (free software; subscription up to $9.95 per month for unlimited international plans)

VPN LogMeIn Hamachi

There's no need to set up complicated VPN (virtual private network) servers to give remote users secure access to the corporate network: Hamachi (which recently became part of LogMeIn) does the job with managed peer-to-peer technology, so no centralized VPN server is necessary. It's easy to set up, easy on the budget, and your subscription gets you LogMeIn's remote desktop system, too. ($5 per month)