Im new to building a pc. This is my setup so far. Im undecided on a case. I was looking for something cheap. (around $50) I need something to keep my system cool since i will be overclocking my cpu. Any suggestions?
 
cpu - intel allendale E2160 1.8ghz $74- I have read that it is highly reccomended to overclock
mobo - GIGABYTE GA-P35-DS3L $90
Memory - Crucial Ballistix 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
vid card - SAPPHIRE  Radeon HD 2600PRO 256MB 128-bit GDDR2 PCI Express x16 CrossFire Supported $60
PSU - Corsair VX 550W Power Supply $80
I may be getting a better video card but nothing spectacular.
 
Do i need more than 1 fan in my case?

video heatsink stock or aftermarket?  you'll want at least a tiny bit of airflow past wherever the hard drive is mounted, and out the back of the case.  depending on video cooling, side panel fans are optional.  Depending on how much air the Power supply draws, you'll want bare minimum 1 fan in the back of the case for overclocking.  the heat has to go up and out somehow, PSU usually cant do all the work.

If you have at least one 120mm intake fan and one 120mm exhaust fan, you should be ok.
 
For overclocking, you will want an oem cooler.  
 
There are many to pick from, and will do the job.

Is Noise an issue? What about case size? Mid or Full tower?

Adding to Killah's comment, what is your budget? Aerocool extreme 3T would be a decent choice, or Coolermaster CM 690.

He says his budget is $50.
 
If you drop the Corsair PSU and use the one in this case instead, it's in your budget. Buy another fan to put in it though.
 
http://www.newegg.com/Product/Prod [...] nata%2bIII
 
If you can stretch your budget, get a coolermaster 690.

some cooler master case are around $50, they have two 120 MM fans.