[RickR10]

I have a MacBook Pro and I'm wondering what I can do to secure the data the best I can in case it's stolen. When I had a Windows Laptop I had a password to log on. I know someone could still get into it without too much trouble with a reinstall of Windows, going through DOS, etc.
My question, what is the best way to do this on a Mac? I set up a logon password so when my screen saver comes up in a minute of no use it requires a password to get back in. Yet all someone has to do is a restart and for some reason it goes straight into OS X without asking for a password. Is there a way to change this?
Is it possible for me to somehow encrypt my data to somehow further protect it? Of course I don't want to do anything that will slow my system down.

[apple007]

I believe if you go into System Preferences / Security and then check "disable automatic login", that should require all user(s) to enter their password upon restart. That's how it works for me, anyway.

[Windowsrookie]

Yes, but all data is still on the HD, unencrypted.

Prefs -> security -> enable File Vault.

[Brad]

Originally Posted by RickR10 Yet all someone has to do is a restart and for some reason it goes straight into OS X without asking for a password. Is there a way to change this?

Uncheck System Preferences -> Accounts -> Login Options -> "Automatically log in as".

Then, be sure System Preferences -> Security -> "Disable automatic login" is checked.

Originally Posted by RickR10 Is it possible for me to somehow encrypt my data to somehow further protect it? Of course I don't want to do anything that will slow my system down.

System Preferences -> Security -> "Turn On FileVault..."

FileVault puts everything in your home folder onto an encrypted disk image that is automatically mounted and unmounted as needed. With that feature, even if someone physically takes your hard drive, he cannot get your personal data without the password to open the disk image.

It'll take a while to move your files. Afterwards, the performance hit should be negligible. I would strongly recommend a full backup before turning on FileVault, though. Not many people have problems with it nowadays, but it used to have a bad reputation.

Also, you may want to enable these options:
System Preferences -> Security -> "Require password to unlock each secure system preference"
System Preferences -> Security -> "Log out after X minutes of inactivity"
System Preferences -> Security -> "Use secure virtual memory"

Furthermore, it would be wise to create a separate admin user and to turn off administrative privileges from your primary account. Details may be found in this thread.