HELP!! Dead Computer

So I went downstairs this morning and turned on the computer. Nothing happens. Plugged in, hooked up and nothing. Green light on back of comp lights up so it is getting power, it just wont power up.
It's relatively ancient and may just have given up the ghost but it still has data on it that i will want to retrieve (though most of the important stuff is backed on external hard drive). I have three questions:
1. Any suggestions on getting my old comp running?
2. If not, how do I get data off of it given it wont power up?
3. Any suggestions on a basic desk top in the $300 to $400 range? Been awhile since i bought a comp so I dont even no what to look for or where to look for it nowadays. Kinda need it ASAP.

Okay. So CRed talked me through it and it is pretty clear that the comp is dead.
Anyone got a good article on processors.

you can take the hard drive(s) out, they should be fine. that's where any of the data you want should be. what model is it? do you have another computer that you can put those hard drives into?

just get a cable to transfer data off the hard drive via usb:
Newegg.com - Vantec 2.5"/3.5"/5.25" SATA/IDE to USB 2.0 Adapter - Model CB-ISATAU2 (http://www.newegg.com/Product/Product.aspx?Item=N82E16812232002)

you can also just pllug it into a new comp.

as for new computers, you can get an awful lot for 300-400 now. i pretty much only use laptops, so no quick recs, but you can get a hell of a deal on friday or monday. it died at the right time.

i3 $380
Newegg.com - Acer Aspire X3 AX3950-UR20P (DT.SE6AA.002) Desktop PC Intel Core i3 540(3.06GHz) 2GB DDR3 500GB HDD Capacity Intel HD Graphics Windows 7 Home Premium 64-Bit (http://www.newegg.com/Product/Product.aspx?Item=N82E16883103455)

cheap laptop $330:
Newegg.com - ASUS A53U-ES21 Notebook AMD Dual-Core Processor E-450(1.65GHz) 15.6" 4GB Memory DDR3 320GB HDD 5400rpm DVD±R/RW AMD Radeon HD 6320 (http://www.newegg.com/Product/Product.aspx?Item=N82E16834230240)

i3 laptop $399:
Newegg.com - lenovo B560 (43302AU) Notebook Intel Core i3 380M(2.53GHz) 15.6" 2GB Memory DDR3 1066 320GB HDD 5400rpm DVD±R/RW Intel HD Graphics (http://www.newegg.com/Product/Product.aspx?Item=N82E16834310606)

wait till black friday though, you might be able to save $100.

Thanks folks. Up and running. Still have to pull from the old hard drive. Going out and getting cable later.