Disconnecting the Battery.....

[sqlpython]

and then resetting all back as before the disconnect.
Exactly what should I pay attention to besides the obvious Clock and Date on the Dash Computer?
  As my signature shows I have an 93 E36 318i.
All the work thus far has been suspension and trim.. Well I did replace the Radio and Heater Control (carefully) w/o a Battery disconnect..

 So now I am faced with the possibility of replacing the Fuel Pump or Fuel Sensor and if I do Must disconnect the Battery before work begins.
How is the Car effected after the battery is reconnected and what do I have to reset..
As an example I have read that in order to get back the Maintainance lights below the Odo reading on the Speedo I must use a special Reset tool after the Oil Change.

[DesktopDave]

If you have the OEM radio you might have to reset the anti-theft code.  BMW computers write to non-volatile memory.  Like an SD card, that memory doesn't require power.

I use a special tool as well.  It's about 5" of wire that jumps pins for a certain amount of time to reset the oil & maint lights.  Pins 7 & 19?  Not sure, don't quote me on that.  That's on the e30, of course.

[sqlpython]

i use a special tool as well. It's about 5" of wire

 rotflmao   :d

[DesktopDave]

I was trying to be funny.  But seriously, it works.  Here's an e36 guy describing his reset tool (a paperclip).

Just be sure you don't jump the wrong terminals.  Putting power to those pins accidentally will cook the DME.  I found a good tutorial about using a small resistor or diode to make sure you don't make an expensive mistake.  Lemme see if I can google it...yup (from Ron Stygar no less):
http://www.unofficialbmw.com/e36/electrical/e36_reset_service_lights.html

[bmwman91]

I recommend soldering a low-current fuse in-line with the wire "tool", just in case. Like 2A or less.

[sqlpython]

Nice Touch!