For Linux there's Seahorse, the Gnome app for managing PGP and SSH Keys. It comes installed by default on Ubuntu. Generating a key and synchronizing it with a key server couldn't be more painless.

For email clients, you can use Thunderbird or Evolution, both of which can handle PGP. There's also a new Chrome/Firefox extension that brings PGP to Webmail interfaces, such as GMail: http://www.mailvelope.com/ ... because of a Firefox limitation, it's kind of slow on Firefox right now, but should get fixed in 27 and it also lacks advanced features (e.g. PGP Mime, or syncing with key servers), but those features are coming.

Linux in general have the best security related tools. Ubuntu's graphical installer for example gives you the option to encrypt either your $HOME directory or your entire hard-drive (with dmcrypt). When formatting an USB Drive, you also have the option to encrypt it. And if you synchronize your files on DropBox or Google Drive, you can quickly create an encrypted folder by means of Encfs / gnome-encfs. And personally, I went full on with encryption. My hard-drive, my USB drives, my Dropbox, my Google Drive storage, all encrypted. I also link to my PGP public key in my email signature, which is cool, as my personal website serves links only through HTTPS.