Word for "collection of information used to make a decision"

I would consider 'dossier'. Whilst it is usually used in a political or legal context, I think it does describe a collection of supporting documents that are collated in order to help make an informed decision about something.

From Mirriam-Webster

Dossier - a group of papers that contain detailed information about someone or something

I would say guide.

a book, pamphlet, etc., giving information, instructions, or advice; handbook: an investment guide.

^{http://dictionary.reference.com/browse/guide}

something that provides a person with guiding information

^{http://www.merriam-webster.com/dictionary/guide}

A guide guides you. It helps you to make a decision. Guide, as a verb, has this meaning also.

to help someone form an opinion or make a decision:

^{http://dictionary.cambridge.org/us/dictionary/business-english/guide_2}

Examples:

Franchise Guide - Helpful information to make a confident investment decision

^{https://www.canadianfranchisedirectory.ca/franchiseguide.aspx}

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The Ministry has produced two election guides – one for voters and one for candidates – in order to make election information easier to find and more user-friendly.

• 2014 Candidates' Guide for Ontario Municipal and School Board Elections

• 2014 Voters' Guide for Ontario Municipal and School Board Elections

^{http://www.mah.gov.on.ca/Page219.aspx}