shuld i be always logged is as a normal user?
Even when you're logged in as Administrator, you are still required to enter your password to give any program full (administrator) access. Like pty said, you have to enter your admin password for the Leap-A virus to work! So this isn't like the nasty Windows viruses.
shuld i use any antivirus with firewalls and all that stuff like on my pc?
If your Mac is connected directly to the Internet (no router), then you should use Mac OS X's built-in Firewall. It's easy to configure, and will be adequate for most people. As for antovirus software, my advice is this: if you don't do anything dumb, you have nothing to be worried about. If you only use commercial software, there's no way you should use it. And when downloading freeware/shareware, make sure it's from a trusted source.
what is the maintance trick for mac's, shuld i divide my hdd for 2 partitions one for system second for my stuff?
Nope, that won't do one bit of good unless you keep one partition unmounted, in which case there's no point in even having it.
In short, Macs are still very secure, so don't sweat it. I download tons of software, I don't have antivirus software, and I've never ever gotten a virus on Mac OS X.
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