I'm by no means an expert, but I've now re-done my own megasquirt 440 conversion twice - once with throttle body injection, then with multi-port. I picked up all my info from megasquirt boards and documents.

Good message board: www.msefi.com

Info on sensors and wiring (megasquirt specific, but 90% of the info can be applied to EFI in general)
http://www.megamanual.com/v22manual/mwire.htm

Same for injectors and fuel supply
http://www.megamanual.com/v22manual/minj.htm

Same for tuning, VE, A/F ratios, etc
http://www.megamanual.com/v22manual/mtune.htm

Ask away and I'll try to answer what I can... there's too much info to just start talking and hope I answer your questions...