Restricing access for users with limited access

[spanishsteps]

hello,

I'm using windows XP professional and my friends would be also using my pc.As an administrator, I've created 2 more accounts, one with administrative access and the other with limited access.
Now,
1.I dont want the user with limited privileges to view few folders.How can I do that??
2.I'd like to also restrict downloading some stuff from the internet for the limited privileged users.
3.My hd is partioned into 3 volumes, is it possible for to restrict access to certain volumes.

Thanks for your time