Ram for Mac Pro (New Mac User)

Sorry but I am brand new to the Mac Pro world and loving every minute of it.
I am just so sorry I wasted so many years on my PC.
Anyway, I wanted to update my new dual quad ram from the two GB standard to something more powerful.
Can anyone suggest the proper type and brand that would be less costly then buying directly from Apple?

Thanks to everyone.

http://www.apple.com/macpro/specs.html

Thanks, though is there a company that you would recommend for Apple memory that you like the best?

I personally don't care for the brand but I believe Kingston are very good.

Ive heard Kingston as well, Apples RAM tends to be more expensive, but does the job.

Also a video on how to install if your interested.

I like OWC. Can't beat these prices with the lifetime warranty!

Thanks again to everybody, especially bryphotoguy for that fantastic hyperlink.
That company is located in my home state and I can't wait to try them out. They sound terrific. What a great welcome to the Mac Forums.

I've never bought RAM from them but I will in the future. I use them for all my needs though. Since they are a few cities over, shipping is like $4 and it arrives next day with UPS Ground. OWC is great. I am thinking of dropping the Blu-ray drive for $200 in my Pro. Not a bad price at all.

200.00 for Blu-ray in the Mac Pro. That in inexpensive to say the least. I will certainly check that out now Blu-ray has won the war.