Most good motherboards have pretty decent integrated sound. The integrated graphics are not excellent so you do need a video card for what you want to do.
-Case
-a GOOD power supply
-motherboard
-processor
-memory
-graphics card
-hard drive
-CD/DVD burner
-Operating system. You can buy the System Builder version to save but you can only use it on one machine forever. The Home Premium is the cheapest buy I would get the Professional.
-Arctic silver for installing the CPU unless you buy a combo.
-You may need to buy some extra cables, especially SATA cables to connect the hard drive and DVD burner. Sometimes it's also a good idea to buy an extra case fan or two, depending on the case you get.
For my builds I generally use Gigabyte or Asus motherboards.
I prefer AMD processors for bang-for-the-buck.
I usually get Corsair memory but there are a few very good brands.
My hard drives are Western Digital. I generally buy 1TB but 500GB is fine. You can add more hard drives later.
Tweak each part to adjust for your budget.
Make sure you properly match CPU, motherboard and memory. Most other things will be universally compatible.
Start off with 8GB of memory. It's probably more than enough. Later you can add 8GB more if you want.
Also start off with the integrated sound. It may be good enough. You can always add an audio card later.
I always read review on Newegg or Amazon before buying.
Price things on Newegg and Amazon. The latter charges no tax for MOST states and fre shipping on orders of $25 or more.
It's really quite easy to put a system together but for a first-timer it's a must to read some online tutorials or watch some YouTube videos.
Good Luck.