Brakes

This is something for those readers who are more technically savy than I am. Should I replace my V brakes with disc brakes?

I've looked into Avid mechanical disk brakes and have heard good things about them. Would it be worth it to invest in them? If so what kind of tires should I get? Regular mountain bike tires or thinner tires since I obviously don't do serious trails?

All this planning has me salivating for the weather to warm up so I can hit the road.