Reddit reviews The Political Ladder: Insider Tips On Getting A Job In Politics

1. Read the numerous how-to's on the subject:
   
   

• http://www.wikihow.com/Get-Started-in-Politics
  
• https://www.amazon.com/Political-Ladder-Insider-Getting-Politics/dp/0615604811
  
  

2. go to an organization that trains you for such purposes:
   

• http://www.wellstone.org/programs/camp-wellstone
  
• http://www.massgop.com/training

The Political Ladder: Insider Tips On Getting A Job In Politics by Alexandra Acker-Lyons

Getting a Job in Politics, and Keeping it by Ben Wetmore

I read both shortly after graduating from college and early on in my career, and they do good job of conveying the the high level of competition for these jobs, they steps you'll need to take, and the sacrifices you'll likely have to make if this is something you're really serious about.