One of the challenges will be keeping the computers secure from a hardware and software perspective.
Depending on the degree of supervision your hardware will have, I would expect that there would have to be a varying degree of physical security for your machines. Some questions to ask would be:
- Will there be a security camera?
- Is the place small enough and have ample supervision?
- Are there any blind spots?
If the hardware is at risk of theft, it may become necessary to physically lock down the hardware with locks and cut-proof wiring to anchor them to furniture.
In terms of software security, again there are some points to consider:
- Are machines from the outside allowed to connect to the LAN?
- Are removable storage devices going to be allowed to connect to the machines?
If machines or storage devices from the outside is allowed onto the local network, this can be a breeding ground for viruses and worms. It would probably be a good idea to have up-to-date antivirus software (with automatic update) on all machines and firewalls with sensible settings for only allowing certain ports to pass.
Not to mention the need for security from the outside world, i.e. the Internet. This is something that can't be ignored, but probably could be performed by having an outward facing firewall that all systems can go through.
Security products which can be centrally controlled will probably come in handy when working with more than a few machines. Considering labor is going to cost money (and yes, your time is also worth money as well), so investing in some system with centralized control will probably make your life much easier.
If the systems are running Windows, I think that Windows Firewall settings can be controlled by Group Policy Objects on Active Directory. I'm aware that there are enterprise security products which allow central control of security software, but again, these two suggestions may be expensive depending on the scale of machines on a network. Again, weigh the costs and benefits.
Also, one additional risk to consider in the security is the danger of spreading viruses and worms through the LAN. This may become a liability if people complain that their machines was infected and caused problems. Perhaps having the patrons sign a waiver would get around this, but I'm not a lawyer, so it would be a good idea to consult a lawyer for legal advice.