What can I 'use' to assist my set-up?

I must be able to have the range ruler on the table as, I need to deploy within range 1 - it follows therefore that I'm allowed to have it to hand.

But how about maneuver templates? If I want to use the width or length of a maneuver template to assist with a particular setup, can I do this?

If I recall correctly, you can use any normal range rulers or maneuver templates, as long as you follow these rules:

1) no custom "setup templates", i.e.; a special template designed to help you put things in formation.

2) if using a range rulers or maneuver templates to place your ships, the templates or rulers cannot extend beyond range 1 of your player edge.

Yep, matt has it right. The exact quote from the X-Wing Tournament Regulations under Tournament Legal Products and Substitutions reads:

Quote

Custom "setup" templates designed to aid players in ship deployment and other custom-made tools are not allowed. Players can use only their range rulers and maneuver templates within range 1 of that player's edge to help them set up formations during deployment.