Check out. My brother also recently started and is helping him a lot
http://www.dotafire.com/dota-2/guides
http://steamcommunity.com/app/570/guides/
http://www.purgegamers.com/welcome-to-dota-you-suck
Best hero to start with i would say:
Dark Seer, no need to worry about last hitting if concept is new to you. Can concentrate on feeling of game and not tunnel vision last hitting + has escape
Lich not too bad, dont need much items to have impact.
Ursa - can forest
Stay away from ( micro units or very squishy non escape heros or one hit / miss):
Meepo, Chen , Rubick, Shadowfiend, Crystal Maiden , Lone Druid , Pudge ( if you cant hook your are useless ) , Mirana, Clock and Invoker
Key items:
Learn how to use armlet
Learn how to use courier
BKB
Blink Dagger / Force Staff