now. i want to buy notebook at USA, but i don't know what's spec for me
I'm Developer (i write program and standard graphic ex: vb.net , Photoshop, sql server...)

but i have money only 500$

what's spec for me?

That's very little money to buy a descent laptop with. I recently bought a laptop from HP which was refurbished for $530. It had AMD processor, 3GB of RAM and 120GB drive and a DVD burner. It might do for what you need but I know from experience that many compilers are optimized for Intel processors. you might have to up your budget to at least $1000, sorry for bad news.

If you have low budget than you will get the Asus and Acer laptop where you can get good configuration in low price. They are also good brands and i have also used Acer laptop and is running good.