For A, AA, AAA and Majors Divisions, the Home Team is responsible for providing a scorekeeper, pitch-counter, and game coordinator. 

SCLL scorekeeper guides:

• Scorekeeper Duties - Basic duties and overview for SCLL scorekeepers
• Scorekeeper Basics - A primer with examples of how to score a game
• Scorekeeper Abbreviations - A handy two-page guide with all the shorthand notations you'll need to score a game

Many leagues are starting to use the GameChanger app for scorekeeping and pitch counting.

• GameChanger scorekeeping - an overview
• GameChanger for managers - an overview
• Using GameChanger on game day
• GameChanger ball-in-play guidelines
  
• GameChanger training -- the official guide from GC
• GameChanger Baseball Scorekeeping Cheat Sheet -- official tip sheet from GC
• GameChanger University - offers lots of videos on how to score different plays
• Download the app

There are a lot of great tutorials online to help learn the basics of scorekeeping. Here are a few resources to get started.

• Sunset Park guide to scorekeeping
• Glover's general scoring instructions
• Scotts Valley Little League scorekeeper presentation
• Keeping a Scorebook - Part 1 (YouTube video)
• Keeping a Scorebook - Part 2 (YouTube video)
• Little League University: What's the Score?  The Basics of Scorekeeping