Hello everyone, yet another newb

I'm an ex-mechanic and I'm tentatively doing a bit of reading up to start with so any educational reading that you feel would help would be much appreciated.

Once I'm a bit better informed, if I take the plunge, I have two - possibly three cars to be getting on with but it's my own discovery 3 that's got me thinking about getting into the world of remapping, partly because it's not cheap for my car and partly for my own curiosity