I just took the plunge and bought myself a new computer to replace my aging MacBook. Here are the specs:

Model: Dell Studio 1555
Processor: Intel Core i5-520M (2.40 GHz)
RAM: 4GB
Graphics Card: ATI Mobility Radeon HD 4570, 512MB
Wireless: Intel Centrino Advanced-N 6200
Hard Drive: 320GB SATA Hard Drive (7200RPM)
OS: Windows 7 64-bit (going to install Ubuntu)

I won't be getting it 'till ~April 20th.

Does anyone have any tips for running Ubuntu on a computer like this? Should I use 64-bit Ubuntu on this? What version of Ubuntu should I use? Will I have to tweak any settings to get it to work (wireless, graphics, etc.)? Any other tips?

Thanks in advance