This depends on how deep you want to go. I honestly recommend starting small.

First, Code by Petzold to make sure you understand how a computer truly works. Then I recommend:

Understanding Microprocessors (Motorola)

8086/8088 Assembly Language Programming

Dissecting DOS

Practical Filesystem Design

FreeBSD Internals

The reason there are so many books is because it’s a big topic. The reason most are old is that things were once much simpler. Modern stuff builds on old, so if you get a good understanding of older stuff, you have an idea of what is happening. From there, I strongly recommend getting a good understanding of UEFI. UEFI will handle most of your system initialization no boot requirements, allowing you to focus on higher level stuff. Prior knowledge of systems will still be a requirement so that you can understand some of the assumptions and choices that UEFI makes.

OSDev is fun. I hope you have a good time.

Great recommendations; a couple i had not come across.

>Understanding Microprocessors (Motorola)

>Dissecting DOS

Can you share or point me to where i can get the above from?

For Dissecting DOS, I recommend eBay, but it is available on Amazon:

https://www.amazon.com/Dissecting-DOS-Code-Level-Operating-S...

The original companion floppy for that is available on archive.org:

https://archive.org/details/dissecting-dos-companion-floppy-...

Understanding Microprocessors is a small book, and currently unavailable anywhere I've seen except for eBay, but it's also normally quite inexpensive.