I think your first option should be to find a distribution that you’re comfortable with first. A lot of users these days like and recommend Ubuntu, but there’s literally hundreds of choices besides that.
PCLinuxOS, Suse, Redhat, etc etc.
Your’e going to get a heavy user support group with Ubuntu, and for some money you can get corporate support from Redhat if not mistaken. All the others fall somehwere in between those two options.
After you find a distribution you like: TrueScrypt.
Some guys consider truecrypt “shady” because so little is shared about it. It doesn’t have the big name attention of PGP for example. But its full disk encryption, 256 bit variation, it works, and it has other features that some call impressive, and others call skirting laws on encryption.
I personally think its a fabulous piece of software.
If you’re running on a netbook, I would honestly suggest going with Ubuntu + Truecrypt. It might not be the fastest, but there’s a certain piece of mind I have recommending the combination to you.