Here are the current system extras as of 12/2/2011. Here is a list of the most common components needed to make a complete system.  This list will include most of the common PARTs like keyboard, mouse, fan controllers, thermal compound, quite system fans and a monitor.  Finally speakers too.  Please note, these are what I feel are the middle of the road, please feel free to call me if you have any questions.  These PARTs are listed as mixed, meaning you do not need to get everything and some PARTs are repeated so you have choices.  I just listed some quality components so you will have an idea of what I will recommend.
  Budget Mid-Range Turbo  

system extras
Amount PART Part Number Description Total
1 fan controller FAN MATE 2 ZALMAN FAN MATE 2 fan controller $9
1 Thermal Paste
AS5-3.5G
Arctic Silver 5 Thermal compound $13
1 Fan S-FLEX SFF21F Scythe Ultra Quite Fan 120mm (NO Noise) $17
1 keyboard MK520 Logitech Keyboard/Mouse (Wireless) $51
1 Mouse G500 Logitech G5 wired mouse (gamer) $61
1 Monitor G235HAbd Acer 23" Wide Screen $140
1 Speakers Promedia 2.1 Klipsch Promedia 2.1 200 watt speakers $150
1 Speaker Z323 Logitech Z323 70 watt speakers $63
1 Case Fans R4-L2S-122B-GP 2 Cooler Master 120mm blue fans $12
1 Keyboard
B2L-00002
 MS Curve Keyboard/Mouse (Wired) $21
1 PSU Fan RR-B10-212P-G1 COOLER MASTER Hyper 212 Plus $26
1 Case Fans R4-S2S-124K-GP 4 Cooler Master 120mm Black Fans $14