Most important commands to use GnuPG

[Saman]

Generating a new keypair
gpg –gen-key

Adding a second email address
gpg –edit-key yourID
adduid or revuid
save or quit

Generating a revocation certificate (mykey key specifier e.g. 40240B2E)
gpg –output revoke.asc –gen-revoke mykey

Listing keys and keys with sigs
gpg –list-keys
gpg –list-sigs

Exporting a public key
gpg –armor -o publicKey.gpg –export email@foo.bar

Exporting a key to a public keyserver
gpg –keyserver blackhole.pca.dfn.de –send-keys email@foo.bar

Importing a public key
gpg –import aPublicKey.gpg

Importing automatically a key
gpg –keyserver blackhole.pca.dfn.de –recv-keys somebody@foo.bar

Once imported, you should check the key
gpg –fingerprint \A key’s fingerprint is verified with the key’s owner. This may be done in person or over the phone or through any other means as long as you can guarantee that you are communicating with the key’s true owner. If the fingerprint you get is the same as the fingerprint the key’s owner gets, then you can be sure that you have a correct copy of the key.

If the owner, the email and the fingerprint fits with your data, you can sign his public key:
gpg –sign-key somebody@foo.bar
gpg –send-key –keyserver blackhole.pca.dfn.de somebody@foo.bar

Deleting a key from your keyring
gpg –delete-keys somebody@foo.bar

Updating key information from keyserver
gpg –refresh-keys

Revoking a key (ONLY if your key was compromised or lost!)
gpg –import revoke.asc
gpg –keyserver blackhole.pca.dfn.de –send-keys email@foo.bar