Important to remember here is, Bitcoin transactions 
not instant are (Yoda-speak!). You can send Bitcoins 
to a friend, but in order to avoid fraud, the nodes in the 
network have to confirm your transaction. You need to 
have 6 confirmations in order to have a 100% confirmed 
transaction. Usually this needs around 10 minutes, but 
since this is a dynamic network, sometimes some more 
time is needed. From the first confirmation on, you are able 
to re-transfer received coins to another wallet.
So, now lets start. As a little welcome gift, go to freebitcoins 
[1] and get your first 0.02 BT for free!
Links:
[1] https://freebitcoins.appspot.com/
[2] If you need a more detailed description about the 
installation of bitcoin-qt, please have a look at https://
en.bitcoin.it/wiki/Getting_started_installing_bitcoin-qt
[3] Also an important further reading is http://bitcoinplaza.
blogspot.co.at/2013/02/how-to-backup-bitcoin-wallet-walletdat.
html where you can find information about how to backup 
your wallet. Remember, if your wallet is lost, your Bitcoins 
are also lost and nobody can give it back to you.