h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I generally find Usborne books are good. Don't be put off by the fact that the books look like they're designed for children. I see there is an "Usborne Encyclopedia of Planet Earth". It sounds like a good start.

I imagine if you did a bit of googling on the web you'd pretty quickly find easy to take in bite sized chunks.
What I've posted is knowledge gained from reading books as a kid, watching TV documentaries on planet formation and continental drift with a smattering of stuff I learned in my chemistry degree (origin of the elements particularly).

Try 'formation of the earth' and 'continental drift' into google as starting points. I'm afraid I don't know any definitive texts for what you ask.

Thanks for all the suggestions. I've a lot to learn about all that's 'out there' computerwise as well as worldwise, but I'm going to set off on this journey and see what I find. Sounds like being interesting. Thanks for 'being there'.

You could try

http://www2.nature.nps.gov/geology/usgsnps/pltec/pltec1.html

as a starting point; USGS are generally pretty good at explaining things.