Need help limiting access to the internet

[berserk]

I am starting to provide some training at my home and I would like to prevent my students to access the internet but be able to access a small intranet I have create.

Anyone can point me to the best way to do this? I would prefer something hardware based then installing software on each PC to limit internet access, thanks.

 

[berserk]

Any specific models you can point me to.