How To Get Started in Reselling/Picking

When I was younger, I used to buy/trade/sell for toys/video games in my neighborhood.  I always enjoyed doing this as well as going to Garage Sales and finding cool treasures.  As I got older, I looked at this only as a hobby not an actual way to earn money.  Last year, my girlfriend and I got into reselling/picking as something we could do together.  It brought back great memories of the fun I used to have as a kid.  

So the question is, how do you get started in reselling/picking?  We will be posting monthly posts about this subject to help others who would like to get started in this.  We are new to this community but hope that we can contribute in helping others and also learn more as well.