Where can i see my BitCoin addresses?
You can use pywallet to look at all the addresses and keys.

The console command listaddressgroupings should also give you all your addresses, grouped by known co-ownership. You can then use dumpprivkey to get the corresponding key.

However, backing up just specific keys is not a recommend practice, you should back up the wallet file. If you do want a more concise method, you should use a client that supports deterministic wallets.