If you're not a gamer, I'd recommend you go with Intel graphics. That comes with each Intel CPU, so you don't need to buy an extra graphics card. They will all play full HD movies without any problems.
At the bottom end, 2 core processors, Intel offers Celeron and Pentium processors. Performance wise there isn't really a big difference. The fastest Pentium processor is about 10% faster in real world than the fastest Celeron processor--while costing you twice as much (USD 42 vs USD 86). BTW, I'm looking at this list of processors:
https://en.wikipedia.org/wiki/Haswell_% ... processors.
If you step it up to buy a Core i3 processor, those will cost about three times as much as a Celeron in mid range (USD 117) but will be 70% faster than a Celeron. Depends on what you can afford. I'd go either with the best Celeron you can afford if on very tight budget, or with the best Core i3 you can afford--you'll notice the difference in speed. Going up further in the line, towards Core i5 or Core i7 it all becomes much faster but also quickly jumps up in price and unless you do many CPU intensive tasks you won't really notice that.
I can help you narrow down further if you want; I regularly build computers to budget for family and recommend friends.
For the other things you mention; 4 GB RAM sounds like a good amount. It will be faster if you take that as 2 x 2 GB RAM (installing two RAM modules is faster than have one RAM module)--but upgrading in the future would mean replacing all the RAM modules. That said, on my 4 year old computer I couldn't find any affordable RAM modules to match the one I had when I wanted to upgrade. So that may be a moot point. Corsair is a good brand BTW.
As for hard disks, I've been very happy with the performance of WD Caviar Green hard disks I installed into two computers earlier this year for family.
