Under the assumption that you do NOT intend to use an encryption scheme (WEP or WPA):
- Turn off SSID discoverability on the router
- Change the default router name to something unique to you (your SSID)
- Use MAC address filtering (see note below)
Additionaly, if you know the MAC addresses of all the computers you intend to allow on the network, you can enable MAC filtering and only allow those computers to connect to your router.
If, however, using WEP and WPA is an option for you, WPA is the preferred encryption scheme, but there are multiple versions. Which scheme you can use will depend on your router.
I would still, personally, disable SSID discoverability after you initially connect all your devices to your network. I would also change the default SSID on your router. However, I wouldn't bother with MAC filtering if you were going to use WPA encryption.
In response to your recent modifications to your question I would go with the following configuration:
- Configure WAP or WEP on your router
- Change your default router name to something unique to you (SSID)
- Connect all your home devices to your network with SSID discoverability ON
- Turn off SSID Discoverability
In the event that you need to connect another device in the future you have two options
- Try to connect to the network by specifying the SSID (this is a trivial task for a computer, but not so trivial for something like a cell phone possibly)
- If you can't specify the SSID, enable discoverabilitiy again on the router, connect to the network, then disable once discovered.