I have a desktop computer that is on 24/7 for various reasons.
I figured that using this computer to mine altcoins might be a useful way to learn about this at a low cost without investing in a system. I know I don't even have a chance with bitcoin as one needs a heavy investment to mine, and I am just looking for a somewhat liquid coin that I could learn about digital wallets and so on without getting burned if I am scammed.
Hi drgon,
I suggest that you look into one or more crypto-currencies that are X11, X13, X15 based. If you have a somewhat modern graphics card (Nvidia/AMD), try using this to do the mining rather than your CPU. The reason for using these algorithms is that SHA256 and sCrypt have or will require asics for mining, so there is no point is mining them with your home PC.
You could choose any coin just for the fun of learning, but maybe take a look at Darkcoin the first X11 coin, with new privacy features being incorporated. Even mining away and getting a few coins every month could turn out to be profitable for you.