1x Aftermarket cooler. One does not simply stock cool their way to the top.
1x Supply of patience.
1x Knowledge about multipliers.
1x knowledge about north bridge frequencies and how they will assist your phenom get even faster
1x knowledge of good PSU's. You can overclock all you like but, if you have a *** PSU you might as well be lighting a fuse on your PC!
Put all the above ingredients into google a mix vigorously.
Now you have the know how and the hardware, you need the hands on.
First off, get rid of your stock cooler, put on your new flash one (I reccomend the CM 212 evo, it's cheap and effective.)
Then have a look at your PSU, how many amps and how many 12V rails does it have? What is the wattage?
Now we're turn out attention to the cooling, clear out your case, make sure your case fans spin freely, and ensure a good airflow.
Right, power her on, and enter your BIOS. Take note of your existing settings, including voltages, temperatures, and current core multipliers.
Enter windows, type in your PSU data, see if it's any good for overclocking, if not, stop there. Enjoy your better CPU fan, and leave it be til you've upgraded your PSU.
If your PSU passes the test, next step is google your CPU, and your current voltag, make sure that your CURRENT stats, fits within the normal operating parameters, ie: It's actually ticking over @ 2.7ghz, and your voltage is around stock.
If that all passes, boot back into your BIOS and as per your google responses, increase your multiplier very very slowly, boot up, run prime 95 in between increases, for at least 5-10 minutes, watch your temps, DO NOT let them get above 65degC!
After you have overclocked as far as you can without crashing your multiplier, take it back to stock and start slowly overclocking your northbridge from 2ghz - ideally 2.5ghz. Again, slowly in low increments, prime95 in between is the key.
Once you have safetly sitting at 2.5 then increase your CPU multiplier step by step and again prime 95 the whole time until you hit your desired target.
After it all said and done, prime95 for at least 15 minutes with both NB and CPU running overclocked and watch your temperatures, so long as nothing goes beyond 65degC you're right as rain and you're done!!!