Seriously. Don't trust the exchanges, don't trust online wallet services, don't trust your anti-virus software, and don't trust anybody online.
If you absolutely must trust someone with your bitcoins, for the love, choose carefully!
1. Put all your coins in a new wallet that has never connected to the network
2. Encrypt that wallet with the maximum security you can find, using the most secure password you can keep track of
3. Delete the plaintext wallet, and distribute the encrypted wallet to every piece of physical media you own, store it online, and send it to several people you trust
Very wise advice, practical tips, a wealth of information. Just knowing this knowledge and experience is here, makes it a little less scarey, for someone about to take a dip in an unknown pool.
Appreciated, looking forward to being able to contribute.