do I need to install a wallet on my PC ?
My advice to all of you is - you are using a distributed cryptocurrency whose strength is the ability to do away with the need for intermediaries and banks, so don't go looking for a bank. By all means learn how to properly secure and back up a wallet yourself before storing lots of money on your own PC, but use the cryptocurrency the way it was meant by using your own light or full node wallet. Install a wallet now and play with it with small amounts, but take my full advice of what else is required to make the most of it.
THIS!
You guys mining should have a real wallet and not be trusting some "Mt Gox" copy to hold your coins for you. I wrote a detailed set of instructions on how to use Armory to have 100% safe, backed up, and recoverable coins plus there's many other wallets out there that are safe and don't belong to some idiot company.
If you're storing your BTC at any place besides YOUR HOUSE then you're really not storing your BTC. You're just accessing someone elses until they decide to stop you from doing so. The one with the private keys is the owner.
I use bitcoin core at home for a full node and wallet, and I use bitcoin wallet on my phone (does not rely on 3rd party servers or systems). Keep bitcoin decentralized and only rely on yourself for keeping your wallet maintained! You'll learn more that way, too.