The most important thing for picking is to evaluate cards and know their value relative to each other. I have an excel list of cards that ranks their value, and mostly go by that for the first half of the picks. After that you do need to take into account mana curve. The minion curve you suggested above is good.

Here is a really good reference for relative card value, which has excel lists: http://www.liquidhearth.com/guides/arena-tier-list. I don't think it includes the new Naxx cards though.

Card advantage is probably the most important concept. This makes cards that either often trade 2 for 1 or cards that let you draw very highly valued. For example, the strongest common card in the game for arena is probably Chillwind Yeti, since it almost always trades for 2 other cards. Spells that often kill more than 1 card are also top cards, such as flamestrike and concecrate.

Class selection is really up to you. I am strongest with Paladin, Priest, Warrior and Hunter. For some reason I suck at Mage even though most people say it is the best class. I stay away from Warlock... it can be good but also can be utterly crap if you get too many big cards.