I'm pretty sure you have heard this over and over again, but I'll say it myself: Bitcoin mining with your CPU will not earn you money. However, if you want to try, minerd (your computer will detect it as a virus, but it's not). It works pretty well on other coins too, although I am not sure if it does Bitcoin (it should, as it has SHA256). I recorded a video tutorial on how to mine Dogecoin with it, and that link is here. Just use the steps I did, except download a bitcoin wallet, request a bitcoin transaction, and set the algorithm to SHA256, not scrypt. Hope this helps.