Need help upgrading my pc.

[jusbat]

Hi. Sorry if this sort of thing has been posted a million times before but I'm looking for help upgrading my pc. My brother gave me his Dell Dimension e520 and I want to make it worthy of playing games.
I'm planning on getting a new processor for Christmas from my parents but the budget is around £50. Then I'm going to buy myself a new graphics card and RAM.
My current specs are:

CPU: Intel Celeron 3.06 GHZ
RAM: 504MB
Graphics Card: Intel G965 Express Chipset Family

More info on this page: http://www.dell.com/us/en/dfh/desktops/dimen_e520/pd.aspx?refid=dimen_e520&cs=22&s=dfh

With the PC I have what products should I buy and do I need to upgrade anything other than graphics card, RAM and processor?

Any help would be greatly appreciated, and feel free to treat me like the n00b I am Thanks

 

[jusbat]

I've been looking at this processor: Intel Pentium Dual Core E6300 2.8GHz Socket 775 2MB Cache Retail Box Processor; and this graphics card: NVIDIA GEFORCE 9500GT but I have no idea if they "fit" my motherboard. I don't know much about building PC's so I really need help on this one. Thanks.

 

[Bodaggit23]

Just get more RAM, a better graphics card, and a new power supply.