ok, so i've taken it into my head that it would be a good thing to install linux on my (empty) portable hard drive. i know i'd be able to set my bios to boot from the usb slot first, so that if it's plugged in when i turn my laptop on grub would appear and i'd choose windows or linux. the problem is that i have no fucking clue how to:

a) install it on the hd
b) keep it from fucking my windows up
c) pick which distro i want (i want something that looks as close to windows as possible, i don't like macs)
d) obtain said distro
e) defend my idea and explain why i want to do this.


also, any help in mentioning a possible benefit to me having linux would be greatly appreciated. like i said, i got this "great idea" but i don't really know why it would be a good thing (not saying it'd be bad, just i don't know why i want to do it)