What deck should be used for a beginner in Netrunner
Jinteki is a bad choice for first time corp player because, with only the starter set, the deck does not have enough ways to generate credits. Having no money means you cannot do much and usually leads to the new player not having fun. If you are trying to teach someone, fun is the whole idea, so this is obviously counter productive.

With core set only decks, I would do Weyland vs Shaper. Both play styles are easy and both run pretty rich.

If you are up to building decks specifically for teaching there are some better options.

Here is a board game geek thread that has a lot of beginner deck suggestions, though some decks here use more than just the core set. Here is a reddit thread that has beginner decks using only the core set.

FFG has actually released decks that it thinks are the best for teaching. These decks leave out a lot of the more complicated mechanics such as Trace. They focus on both players setting up their side of the board quickly so there is almost always an "end game". 

Note that the Demo decks clearly don't follow normal deck building rules. They are purely for teaching. In addition they only require 6 points to win by agenda points.

  Jinteki - Personal Evolution
  Agendas:
  3x Priority Requisition
  3x Nisei mk2
  1x Unorthodox Predictions
  Operations:
  3x Hedge Fund
  1x Restructure
  2x Trick of Light
  2x Neural Emp
  Assets:
  2x Melange Mining Corp.
  2x Private Contracts
  2x Snare!
  2x Project Junebug
  ICE:
  3x Wall of Thorns
  2x Bastion
  2x Wall of Static
  3x Enigma
  3x Chum
  3x Neural Katana




  Shaper - Kate "Mac" McCaffrey
  Events:
  3x Sure Gamble
  2x Modded
  2x Freelance Coding Contract
  2x The Maker's Eye
  2x Infiltration
  Resources:
  1x Professional Contacts
  1x Aesop's Pawnshop
  1x Ice analyzer
  2x Armitage Codebusting
  2x Public Sympathy
  Hardware:
  3x Akamatsu Mem Chip
  Programs:
  2x Magnum Opus
  1x Net Shield
  Icebreakers:
  2x Battering Ram
  2x Gordian Blade
  2x Pipeline