Bitcoin mining (how to mine)

what are programs i can use to mine bitcoins?

Its really not worth it to mine with a PC anymore, a company called butterfly labs released ASIC miners (dedicated miners with ridiculous hashrates) and the mining is dominated by that now.  You'll spend far more money in electricity than your bitcoins will potentially ever be worth.  If you want to get into mining litecoin is probably the way to go for now.

All this is because bitcoin increases its difficulty to maintain a constant rate of coin generation :

I currently mine litecoin, and this can get you what you need to know