Building my first computer

I am wanting to build a computer that I can use as a pvr and do minor video encoding/editing. I am a new at assembling/shopping for computer hardware like this so any help would be great.

I really could use some suggestions on a motherboard and CPU and even a decent graphics card to purchase. I have an athlon now, so I would like to stay where I am comfortable and purchase another AMD. Also, I dont do intense gaming and I am not really sure about sli duel graphics cards. If anybody could suggest a decent nvidia card i would appreciate it.

If possible I would like to use my computer as a backup unit/pvr mostly.

This is a good place to start:
http://www.htpcnews.com/

This article may give you some ideas:
http://www.anandtech.com/guides/showdoc.aspx?i=2535

Ok, first, here are two sites that have good pc building guides. Read through, and they should help you visualize what you'd need to do. The parts they use aren't the important thing, it's how they put the parts together.
http://sysbuild.corsairmemory.com/report.aspx?id=2&sid=2
http://www.hardwarezone.com/guides/amd-socket939/

Here's an interesting site about quiet computing as well.
http://www.silentpcreview.com/

If you don't do intense gaming, then one video card should be more than enough. Sli is just having two video cards working together to make the game run even faster, but I doubt you'd need that.

Here's a possible parts list.
http://www.newegg.com/Product/Product.asp?Item=N82E16813186086
http://www.newegg.com/Product/Product.asp?Item=N82E16819103537
OR(depending on budget)
http://www.newegg.com/Product/Product.asp?Item=N82E16819103562
http://www.newegg.com/Product/Product.asp?Item=N82E16820145440
http://www.newegg.com/Product/Product.asp?Item=N82E16827152058
http://www.newegg.com/Product/Product.asp?Item=N82E16811124109
http://www.newegg.com/Product/Product.asp?Item=N82E16822144701
+win xp(whatever version you want)
+other stuff, like a tv tuner, kb, mouse, monitor, etc if needed.