Welcome to the forum!
I started by going to the library.
Then I found the predecessor to this forum and started reading. You'll learn way more here than you'll learn from the books, but they are useful, too. I made it my goal to read everything ever written.
Then I went to an aspiring innkeeper seminar by Kathleen Panek, Gillum House B&B, Shinnston, WV.
I also interviewed innkeepers as I was able... but not until I'd done most of the prior research above. I scheduled tours with them, in advance, and was respectful of their time. But hands on tours were also very educational--every innkeeper does things so differently!
All four methods were highly educational and allowed us to open with a minimum of hassles and missteps. (We're still new, but so far so good!)
Good luck to you!!
=)
Kk.