Below are some free tools to manage your SMB network.
https://www.spiceworks.com/ Spiceworks Help Desk and Inventory
Spiceworks Help Desk and Inventory is one of the most popular free tools among IT professionals in the SMB sector. It’s easy to use, is mobile friendly, and helps you get a good overview of your network along with setting in place a good helpdesk for employees to submit tickets and to track items. If you want to know whats on your network, from devices to software, to users, this can show you.
https://3cx.com 3CX VOIP PBX
3CX is a voip phone system that you can install on Windows or Linux. It has a free version that almost any small business could benefit from if they are currently using an analog system or something given to them by their local telephone company. You can install it in the cloud for under $5 a month and have a redundant and modern phone system with a significantly smaller phone bill.
https://www.manageengine.com/products/desktop-central/ Desktop Central (Patching and Control)
One of the best ways to keep your network secure is to keep your computers updated. Not just Windows updates, but third party applications like Adobe Reader and Flash. It is also extremely helpful to be able to login remotely to your PC’s when you are not around. Desktop Central does both of these things and so much more. The best part is you can support up to 25 computers for free.
https://opendns.com Cisco OpenDNS
You have to use a DNS server in order to use the internet. Why wouldn’t you use one that helps protect your network from malware, viruses, spam, phishing, and all other kinds of threats? Simply point your external DNS server to use OpenDNS and it starts working. Make a free account to be able to monitor (limited) what it is doing and how it is protecting your network.
https://pfsense.org/ Pfsense Open Source Router
You didn’t install a residential grade door lock on your business front door, and you shouldn’t use a home router/firewall for your business. Pfsense is an enterprise grade router and firewall that cost nothing but the hardware to run it on. With the ability to do what almost every paid business router can do, there is no reason not to use this if you currently do not have a commercial firewall.