They come in for a lot of stick, but Haynes are great. Perhaps its because I'm British, but somehow they meet my needs.
I bought several US books regarding EMS and Efi to find them packed with endless pictures of obsolete american brands of ECUs (are they paid for product placement?) and a strange mixture of simplistic advice about how to splice wires placed immediately alongside the most horrendously complex projects involving custom alterations of 1950s cars into chromed and turbocharged amazing machines.
In contrast, good old Haynes explains how engine management works with minimal pizzaz. It goes on to explain how, with a £30 voltmeter, I can test the various sensors and actuators on my car, diagnose faults and change parts. For someone at home with tuning pre-1980s cars, this was perfect to help me demystify the whole 'EFI' scene. Strongly recommended for the 50 year old frustrated DIY mechanic who always asssumed engine management and fuel injection was beyond him. Its not; and Haynes prove that.