If they might stay, I pad my calendar so someone doesn't book it when I could just keep the current person.

Separate checking accounts not required, but you need to maintain separate books and records.The TREC requirement is correct, but odds of enforcement seem low.

Maybe Evolve would allow you to transfer all bookings you currently have for a fee?

I also completley share his advice on a bias for action.If you are interested in a good book reference with checklist like models, check out "The Perfect Investment" by Paul Moore and "The Book on Investing in Real Estate with No and Low Money Down" by Brandon Turner, both also available in audio versions.

Do you guys use quick books or google doc sheets ?

It's the one thing that will take your from analysis paralysis to action because it's the only way to put the learning you've done from podcasts and books into real life - by talking with others who have done what you want to do or who are trying to do what you want to do.Get your finances set and talk to a lender so you know what you can afford.Stay local.

Are you doing your own sets of books?

As @Allen Duan said 1-2 bedroom are the sweet spot for traveling nurses, but that being said we have a 4/2 that's stayed booked consistently.

Does anyone have any good recommendations on books or accounts I can follow or read to learn more? 

@Bracken Bjorn - highly recommend David Greene's long distance investing book!