First i would download the blockchain. You can get it from a trusted source, as above, or just wait and let bitcoin-QT download the whole thing. It may take days, but you don't need to do anything except wait for synchronization.
Once you are caught up you can go to "receiving" in QT and create a new receiving address. That address is what you want. If you send bitcoin from blockchain.info to that address it will show up in your QT wallet. If you send it before you are synchronized it will still work, but you wont see the balance in qt until your synced. 

P.S. once you have transferred funds to QT you should make a backup copy of your wallet.dat file.
That's all.