Bitcoin 0.8.5 - Paper wallet since some answers seem to be outdated, I ask now explicit for version 0.8.5 of the official BitcoinQT-client.

I want to save my wallet to paper and hide them in a safe - could you tell me if following points look valid?

This topic seems really complex, I dont know why there is not an easy option like "Export wallet to pdf"...

Ok so here we go:

1) I would like to export my private keys to textfile?
(How does it work?) I only see how it works for one single private/public key-pair?

2) Print it out and hide it in safe

3) When I do a transaction or receive something, i should print out again all private keys, because otherwise something can be lost?

Thanks!
As of the 0.8.x series, the reference client does not support paper wallets. You can export individual keys, and print them to paper, but you are very likely to shoot yourself in the foot unless you're familiar with the implementation details.

In particular, change (the difference in value between coins used to create your transaction, and the amount being sent) is sent to a fresh address in order to increase privacy of the system. When you're using a paper wallet, you will likely miss these, as well as key pool entries.

There is support planned for deterministic wallets (BIP32), which means a single backup of a wallet seed will be enough to create the wallet. This may or may not end up in 0.9, though.

The reason why no "Export wallet to PDF" exists, is exactly because in the current model, this would result in many misconceptions and lost coins. Without deterministic key generation, no immutable dump of the wallet can survive (a series of) spends.