Extremely Cheap Build - Help needed

Looking for some advice on a new build I'm putting together for a friend. He has a very low budget for me. He doesn't need a monitor.

He's going to be using the computer for web browsing, picture viewing/sharing, video viewing/sharing and mild if any picture/video editing. He also wants to be able to burn CDs/DVDs when he needs to. He will be using iTunes for his music collection and the iPod's that sync with his computer. He will use Chrome as his web browser. I want to build this as cheap as possible, but I also want him to be able to do everything he needs to do without any sluggishness.. He won't need any antivirus software after I talk to him about how to avoid viruses. He will have very little other software on there as well. My ultimate goal is to build a very fast, responsive system that can also do everything he needs it to do.

I'm fairly confident he won't need a graphics card. Other than video editing, the actual usage of it will be minimal. He is not going to be playing games. If I can afford a cheap one just to take the stress off the CPU I will.

I'm going AMD for this build, there's no way I could stay under budget if I didn't. From what I know of what he needs, I was going to get him a dual-core CPU. I didn't think shelling out more money for a lower-clocked quad-core would be cost-effective or useful for him. But, I'm no expert.  

Any help and advice is extremely useful! I just need CPU/motherboard combinations, really. The rest is pretty simple. If anyone wants to suggest something else that would be very nice as well! Also PSU, and HDD space (I'm going WD, without question) would be nice if suggested.  

Thanks! (I'm not mentioning a max in the budget, because I know he will say yes no matter how far I go above if I tell him to, but he offered $250. I told him to expect around $300-$350. Again, that's just a rough approximation.)