Need an Ideal Build For Parents, $500 Budget

I need to  build a pc for my folks. Unsure of what exact hardware to go with. They need it for general use, web surfing, mom has college classes she takes online, dad likes to mess around with some adobe programs. Would also need it capable of light gaming. Dad likes to play World of Tanks/Airplanes etc. They have a $500 budget(Don't worry about shipping, monitor, or m/k) . We are in the U.S.

ALSO- I can get windows 8.1 Pro for $75 through m.s. for being a college student, so that leaves $425 (give or take $20 if it makes a decent performance increase) to build around.

I appreciate the help.

This is a decent starting point. The APU is probably not the best for Adobe programs but as long as your dad isn't doing anything super serious it should be just fine. 

PCPartPicker part list: http://pcpartpicker.com/p/8h7zpg 
Price breakdown by merchant: http://pcpartpicker.com/p/8h7zpg/by_merchant/

CPU: AMD A10-7800 3.5GHz Quad-Core Processor ($161.29 @ Amazon)  
Motherboard: Asus A55BM-E Micro ATX FM2+ Motherboard ($39.99 @ Micro Center)  
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($72.00 @ Newegg)  
Storage: Western Digital BLACK SERIES 320GB 2.5" 7200RPM Internal Hard Drive ($54.10 @ Amazon)  
Case: Silverstone PS08B (Black) MicroATX Mid Tower Case ($34.99 @ Amazon)  
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply ($15.99 @ Newegg)  
Total: $378.36
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-09-29 18:56 EDT-0400

I have found that I can get a 1TB Blue drive for the same price as that 320GB. It's not showing $378.36 for me, it's showing around $400 after everything for me and that's with Amazon Prime. 

I was originally gonna go with a Athlon 860k and a GTX 750 but that would put me over budget more than I'd like. $5-20 I can handle. So after playing around a bit and looking at some benchmarks and comparisons, I came up with this.  http://pcpartpicker.com/p/VnwNsY

I'd appreciate any feedback towards this list.

I tweaked it a little. FX-4300 + 260x (2GB card) should stomp the APU. $23 over budget but you may be able to work around that. http://pcpartpicker.com/p/CDGKnQ