this is a bit of an essay. also, a few more options for securing things occurred to me as i wrote this, so it's a little bit of a shambles, but there are a few options you have here for nailing things down. hope this helps
first off, under parental controls, if you check the 'finder' checkbox, you can specify which programs he can or can't open, including and not limited to firefox. check it out.
also, from within itunes, you can disable the itunes music store and require an admin password to re-activate it. to do this, open itunes, then, under the itunes menu, select "preferences"
go to the "parental" tab, it's the last on the right.
you may need to open the padlock by clicking on it to make any changes. you want to check the "disable itunes store" box. then lock the padlock by clicking on it so he can't re-activate it.
then, i would do these steps on his computer.
go to the apple menu, and choose "system preferences" go to "security" it's in the top row, near the right.
check the "require password to unlock each secure system preference" checkbox. (try saying that 10 times fast) this is a handy little setting which will lock down all the system preferences that require your admin password
lock the padlock, then click "show all" up the top to save the setting.
to put a password on your wireless connection, you'll actually need to login to the router iteself to configure it. you can do this from any computer that has access to your network, not just his. (personally, i have had that many problems with d-link that i went and bought an airport extreme - my dlink wouldn't let me put a password on it due to a problem with the firmware. the setting was there, but it wouldn't activate
see how you go, you may have more luck than i did)
to do this, you'll need to log in to your router.
on your computer (or his, doesn't matter) go to system preferences again.
select "network" it's in the third row down, second from the left.
if you have a list of connections there (such as airport, ethernet etc), double click on airport.
if you don't have a list, under the "show" dropdown menu at the top, select "airport"
click on the "tcp/ip" tab.
(at this point, if you really want to mess things up in a totally recoverable way, change the "Configure IPv4" dropdown menu to "manually", leave the settings empty or with "0.0.0.0", and then lock the padlock. do this on his computer. dhcp, which is probably what it was previously using, is a technology where the computer will detect the network settings for the network that it's connected to. if you manually set it to "0.0.0.0", the computer effectively can't join any networks, wired or wireless. when you decide that he can have his internet back, change it back to dhcp, and it'll be able to find the networks again this solution just occurred to me as i was writing this)
if you still want to go ahead and put a password on the network, take note of the numbers in the "router" field.
open up safari, or any web browser, and type the numbers in, including the "."s. no www, just exactly as it appears in the "router" field.
you may get a popup box asking for a username and password, or you may get a login page. regardless, dlink use the username "admin" and password either blank or "admin" depending on the model. you can change the username and password down the track if you want.
this is where it gets tricky. dlink have changed the configuration for their routers that many times that i can't tell you where to look to secure the network. on mine, it was under a setting called "wireless"
you're looking for something called "security", that will have options "WEP" and "WPA". i'm not a network techie, so i can't tell you the difference technically, but one of them requires a password of a specific length (often 8 or 16 characters) in hexadecimal (that just means that the only characters you can use are "a" through the "f" and "0" through to "9"). this one is a pain to configure and for obvious reasons, it's really hard to remember the password. it's more secure, but unless you're the cia, you're probably not going to need to use this option.
the other one will allow you to use an actual password that you choose. any characters, any length. i would recommend this option.
i'm sorry, but i can't remember which is which.
the other technicality of the dlink routers, is that you need to find the button to "save settings and restart router" or something similar, in order for the password to take effect.it may be at the bottom of every page, it may under a specific "settings" page. find this, and click it, then wait for your router to reboot. if it's worked, you'll then need to reconnect using airport and put in your password to join the network.
if, for whatever reason, you can't get back onto the wireless network after doing this, you can just hook up a direct connection with the router using network cable, and connect to the router and change the settings again.
hope this is what you need, let me know how you go
