If you're looking to start mining BitCoins, there are several sites where you can do it. The easiest way to earn BitCoins quickly is to mine on a pool - mine with other workers, so you can mine Bitcoins faster. Remember, you should invest on good equipment! Here's the list of sites:
Bitcoincz - Mining;
If you know other BitCoin Mining Pool sites, leave a comment!
LiteCoins Donations: LXHxyzzmpGq6Jp8xJDeLPyJYmR1SAFrDpg
BitCoins Donations: 1DCsCVzimktDfHmwnZ6Xq7JeABeE6X37Tm