To keep your coins safe you can use Electrum. It will generate a "seed" that you need to print or write down and keep it safe. The wallet will use that seed to generate addresses you can use to receive bitcoins. If you are into Linux, you can use a Tails DVD to generate the seed in a clean environment, which is safer. I think the last version added Electrum so you won't need to install anything extra.
Another option is to use multi-signature online wallets like Coinkite (I think Coinbase offers multi-signature too now).
You could simply buy them, take your wallet offline (store it on a couple of USB sticks and check on them periodically to make sure they're all still readable).
Buying bitcoin is not an investment, it's mostly a gamble.
If from US just sign up at coinbase, add bank account, and buy them.