Hearthstone - How to create a viable deck when starting out by robhimself

Going to write a short guide here explaining hidden quests, competitively viable legend decks that you can craft for minimal dust by playing AI, and most importantly, make fun of newer generation gamers who think everything should be handed to them without working for anything.
 
Hidden Quests:
http://hearthstone.gamepedia.com/Quest

• First Blood | Complete a game in Play mode. | 1 Classic Card Pack.
• The Duelist | Play 3 games in Play mode. | 100 Gold.
• Level Up | Get any class to level 10. | 1 Classic Card Pack.
• Crafting Time | Disenchant a card. | 95 arcane dust.
• Enter The Arena | Enter The Arena. | 1 Arena Credit.
• Chicken Dinner | Win 100 games in any mode. | 300 Gold.
• Ready to Go! | Unlock every Hero. | 100 Gold.
• Crushed Them All! | Defeat every Expert AI Hero. | 100 Gold.
• Got the Basics! | Collect every card in the Basic Set. | 100 Gold.
• GvG Event | Log in during event. | 3 GvG packs.
• GvG Event | Log in during event. | 1 Arena Credit.

Level all classes to 10 playing AI. Defeat all expert AI. Once these two objectives are done you will have nearly (or exactly) 100 matches played.

Total: 700g, 2 arena credits, 95 arcane dust, and 5 free packs.

That will on average, be over 1000-1500 free dust that you can use to craft cards.

An important tip; disenchant all of the cards you don't need. Bad rares, bad legendaries, bad epics, etc. You can figure out which cards are worth playing from tournament decklists.

The Decks:
Assuming you want to get legend immediately since the only thing holding you down in the rank 45's is your low card base, the best option would be spending $25 on Naxxramas to get access to all of the top tier cards released in the expansion.

If you want to stay completely F2P, you can grind the gold for Naxx, so I will post some deck lists and tell you what cards to craft for the most optimal decks in the meanwhile.

The two cheapest and most competitively viable decks are Warlock Zoo and Hunter (if you have Naxxramas cards regarding Hunter). Shaman, Mage, and Mech Rogue decks are also very cheap.

These decks are just a starter guide to give you an idea on what cards to craft. You can find alternative deck lists all over the forums, deck lists posted by pros, etc.

Warlock:
Without Naxx/GvG Cards: 1240 Dust
With GvG Cards: 1360 Dust
With Naxx Cards: 1120 Dust
There are several variations of this deck, you can find them all over this subreddit, other forums and tournament decklists if you want to follow them card for card. This is just for guidance. However, all deck variations hover around 1,000-1,500 dust.

Hunter:
With Naxx Cards: 800 Dust
Likewise with Naxx Hunter, several variations. If you have Naxx cards they all fall within the 700-1,000 dust range.

Shaman:
With GvG: 1320 Dust

Mage:
With GvG: 2700 dust

Other Cheap Decks:
There are several decks within the 1,000-2,500 range that constantly reach Legend, search yourself you lazy pleb. But for the lazy: Rogue Mech, Mage Mech, Druid Mech, GvG Shaman, etc.
Tournament Decks
CompetitiveHS
Sticky Threads from /r/Hearthstone
Basic & Naxxramas Deck Guide for All Classes
Hearthstone Intermediate Guide
Beginner's Guide to Consistency and Success in Arena

Source: hearth