Simply go into the settings and click on parental settings. It should be pretty easy from there.
No.
you cant put movies on a dsi
slide an put you passcode in
you have to download it from their site.
Here is the answer for dsi. you can use an sd card to put the music on your dsi.
I do not know but i do know that you can put an SD card to put songs on the DSi.
The Nintendo DSi has a built-in web browser.
No, but if you wanted to, you could trade in the DSi, then put some more money towards it.
Put the dsi's together while they are connecting for other person
Not individual games no, but you can passcode lock certain game ratings through parental settings or you can just put a passcode on certain accounts through account settings
you cannot put a usb in a dsi you can get thecable of ebay around 5 to 10 pounds
First of all, get an SD card. Put it in your computer, and import music to it. Put it in your DSi, and play it in the music thing on your DSi. :D