For your first question, you could have a look at The Elements of Computing Systems, by Nisan and Schocken. It covers the workings of a computer from logic gates, via the CPU to programming languages and the OS.

The website of the book is here; via the 'Study Plan' link you can even find most of the book online, and some presentations based on it - those could be useful to get a quick idea of whether the book is right for you.

For your first question, you could have a look at The Elements of Computing Systems, by Nisan and Schocken. It covers the workings of a computer from logic gates, via the CPU to programming languages and the OS.

The website of the book is here; via the 'Study Plan' link you can even find most of the book online, and some presentations based on it - those could be useful to get a quick idea of whether the book is right for you.