Getting started w/ tube equipment

I am interested in tubed components and, knowing nothing about them, am wondering what a good place to start is.

Some reference material that might explain advantages/disadvantages to integrated or separate.

What to look for to match components and perhaps some suggestions for a good place to start (brand, model, etc.)

I recognize this is highly subjective based on individual style and preference, rooms, etc. but i need to start somewhere...

Thanks.