Newbie - How knowledgeable do I need to be in regard to home repairs?

[Josh Foret]

Planning to purchase a duplex in DFW for my first investment property as described in http://www.biggerpockets.com/renewsblog/2015/03/25...

Considering I will be living in one side of the property, how knowledgeable do I need to be in regards to appliance related issues? 

I listened to @Darren Sager mention in his duplex podcast that he makes tenants sign an agreement to pay for a company that handles all of those issues. Is this an option for a newbie investor? Would something like that be included in the rent?

I apologize if this is already a popular thread. I'm new and still learning how to navigate the forum.