from what i've heard dota is hard to learn if you are new but try on www.dotafire.com you might find something useful there i've played mine couple of times didn't like it because i suck at it lol also if you are into mobas try league of legends its quite easyer to learn than dota
i have got dota2 i play it mostly these 6 past days; when i strated it was strange game for me, but i used to learn it with matches, first play vs co bots, choose eazy level because you wont learn if you play medium or even hard directly, that match vs co bots will be 5 players(you with them) vs dota bots, choose mode All pick that allow you to learn all heros and to see the adventage using everyone, in game you have some power, normal power(that everyone get got it) and personal one, that you will win them with level, you have to win money (GOLD) to buy & increase your power, in killing damage moving speed and to defend your body(you will learn them by time), so shortly and first step try to get level fast, earn money fast, and to survive as much as possible, and play like 6 games or so you will understand ;)
Use some youtube tuto to understand better that what i did
I too have recently started playing DotA 2. I am completely new to this game genre and was clueless as to 'what the fuck is going on here'. Fortunately however there are lots of text and video guides out there. Few of them are the following.
Also you can try watching DotA 2 pro players' streams and demos.
Initially in live matches others will most likely rape you in the face. So as #4 said start by playing solo against bots or co-op bot matches. When I started I found easy bots too hardcore for me so I played with 'easier' bots.