if you only stored it on that computer I don't think it's possible to restore. Please see this link: https://en.bitcoin.it/wiki/Securing_your_wallet
2 - I have "encrypted" my wallet, and set the password, however it still lets me log into it without any authentication at all. Is the password only needed to send money - as in anyone can view my wallet by clicking on it?
I think it's public how much each bitcoin address (public key hash) has in general. If somebody gets access to your wallet.dat they will be able to see all the bitcoin addresses in the wallet but not spend without the password to obtain the private key necessary to spend any bitcoins.
3 - After you mine coins, your pool pays you out after a certain amount. Would you reccomend to leave it in your wallet until you want to sell it?
Bitcoin wallet's are supposed to store coins (that is one of the goals of the system.) It's recommended to secure your wallet using this method before accumulating coins from any source.
https://en.bitcoin.it/wiki/Securing_your_wallet
4 - Can you "store" money on an exchange such as btc-e or mtgox until you choose to sell it? or is it only meant for current orders like a stock exchange?
4 - What is the most efficient way to convert cryptocoins into currency or a into paypal account?
sell to peer that you know. Otherwise mtgox.
5 - Has anyone every sold crypto coins in person? (AKA Craigslist) I think this would be funny. Meeting someone in person, handing over cash to a guy, who then opens up a laptop and sends you crypto currency.
See above.
1: Backup. Keep a copy of your wallet (just like all other important digitial information).
2: Spot on. Password only needed for sending.
3: Keeping in wallet seems like a good idea to me
4: Yes you can keep BTC in your account on the exchanges
5: Not me.
If you've not already seen, then https://en.bitcoin.it/wiki/Main_Page is a source of info.
Thanks guys, you have both been very helpful.