First welcome to the newbie section of the board
Sorry for you but with a typical computer you CAN'T mine bitcoin
Now the difficulty for mining bitcoin is so high than you have to get an ASIC board and it costs you 10000 dollars if you find someone who want to sell it to you ...
Now you can't use your graphic card for mining bitcoin (SHA 256) but you can if you choose the popular Litecoin instead (Scrypt)
You need a good graphic card (preference : ATI/AMD not NVIDIA !) For mining get the best quality/price ATI 7970 (+/- $300)
With this you can get a 800 Kh mining speed
Advices :
Use your old computer (2010) but don't use your laptops ( only graphic card is important not the CPU !)
Buy an ATI graphic card 7970 ( +/- $300)
https://litecoin.info/Mining_hardware_comparisonJoin a pool (don't mine solo difficult is too high !)
Use Cgminer (the best and versatile app for mining) 3.7.2 (version after it's only for ASIC)
With this hardware you can expect mining for $10 dollars per day (I don't count electricity cost) per day (caution it decrease all the time !)
http://dustcoin.com/Find a tutorial on the net for setting all that ATI 7970 , cgminer (install and fine tuning) , drivers ATI / Catalyst
Don't worry for the warmth ( software can check and interrupt mining if it gets hot !)
Good luck !