Los Santos can be overwhelming at times, and there is a lot to learn both about surroundings and mechanics. Fear not as Rockstar have seen it fit to publish Grand Theft Auto V: The Manual on AppStore.
"GTAV: The Manual is the official manual app for Grand Theft Auto V. Contains over 100 pages covering everything from Game Controls, and Features to a tour through the local neighborhoods and activities across Los Santos and Blaine County - plus a special interactive version of the game map to zoom in and explore."