Home Based Business, Taxes and How to protect myself, my investment?

[Angelique F.]

I just purchased my first (buy & hold) investment property the other day........FINALLY!   The property is located 166 miles (round trip) from my primary residence.   I've been reading about how I could claim the mileage or gas on my taxes, (IF) I have a home based business.  

What does that mean exactly?  Does it mean I need to register myself as a small business with my state or something before I can deduct the insurmountable expenses I'm about to incur traveling back and forth to the property while it is being rehabbed.

Then my second most concern is how do I protect myself and the property from lawsuits once it's rented?  I only have the one property as I learn more about how this all works, so will just having the home insured be enough to protect myself. 

Speaking of insurance, the home is only insured for Dwelling and Garage Frame.  Do I need more coverage ie liability in case a contractor falls off a ladder or something?

Thanks