This site gives 10 tips to improve security and privacy. Of course most of these can be adapted for the PC as well if you look at the basic concepts.
1. Disable “Open safe files after downloading”
2. Disable automatic login
3. Lock screen when away
4. Use 1Password to create and store internet passwords
” Some of this functionality can be replicated for free using Keychain Access, but the real benefit of 1Password is its automation, and the fact that it works in Safari, Firefox and on your iPhone so you don’t have to save your passwords separately for each.”
5. Turn on the firewall
Mac OS X comes with a built in firewall, but it is actually turned off by default. You can turn it on in the Security section of
6. Use Little Snitch (Personally, I find Little Snitch to be annoying, but it probably does improve security. lcw)
7. Encrypt and hide your private files
8. Use FileVault (Even the author says he doesn’t use this option. Personally I think it makes it more likely I will lose data. It will protect it from me and others.)
9. Secure Empty Trash
10. Securely erase an entire hard disk
Of course, there is much more detail on the web site.
Read it here.