That fully depends on what are you going to do with that PC.
But one component that is missing is computer inclined friend. I heard of too much failures if assembled wrong. If you want to do it yourself, never use force to plug something in, check everything before connecting power, read assembling instructions at least 7 times. Or 10. Not less!
If you want to play games - external video card is a must. Built-in is only good for internet/office. If games are not for you - don't.
Moreover, if you want to listen music and have a good stereo or at least $10 phones -
DO BUY decent sound card!
Sound quality of built-in soundcard is
always horrible, with noices, hum and distortions even on silence time! Look at Creative Labs (best soundcards from beginning of 90s in consumer segment) or Asus at that site. They all would work nice with games or home cinema setup if needed, and should produce good quality audio for music and films. USB version can be better, cause you can unplug it anytime and plug into laptop for better sound of laptop.
But if you take sound more seriously (as I do) try to find something in Pro segment. They would not give you 3D effects, 99+1 channels and other consumer junk (sorry, no surround for home cinema), they just give crystal clear sound, always. Can get under $100 especially used on ebay. But it's a whole different story
I suppose CPU has installed heat sink and fan? I would call them and ask that.
You will need keyboard, mouse and monitor. Try to get IPS-type monitor. As big as you can afford. IPS monitors are much better to look at SOYP forums!!!
)) And are not much expencive than other types (but some of them can be expencive...). Buying monitor you should check if it has included HDMI cable, if not - buy it. You do not want to have nice modern PC with fancy new monitor connected by 30-years-old analog cable (which is always included
. And check that monitor has same HDMI input (DVI could be also good option, but your kit has only analog VGA and HDMI output, NO DVI).
Keyboard - Mitsumi, Mouse - logitech. Buy simple, cheap models but of those brands - you do not need "fancy", but you do not want to change them after one month - keyboard and mouse take A LOT of abuse, and they die fast if made buy unknown/new chinese brand. That site do not have something in keyb/mouse range I can recommend.
Also, would you be Skype-ing? Than some webcam and mic or headset. I would suggest cheap mic for Skype and good headphones
Also, on headphones - you can buy amazing sounding Koss KSC-75 for $15. It's nothing, belive me, and no other will give you that sound for the price. They sound almost like $50 Koss Porta Pro, an all-time classics. Though, my professional $100 Senheisers are better, but much bigger
