If you have a small collection, then it's all about crafting multiple rares/epics to fill out a basic deck. Don't start with legendaries. I hit rank 5 two seasons in a row without a single legendary in my deck, so you really just need to figure out one deck you want to make that you can afford now.
I'm just not into delaying damage. I like solutions to problems.
I've seen Rogues use Doomsayer + Conceal effectively.
Good Paladin ideas.
How do I go about deciding which decks I'm closest to building? Is there any place I can enter all my cards and have it tell me which decks I'm close to building and which cards I need?