1 - Make a topic on gamefaqs, or any other dota related board/forum for that matter. Chances are someone will give you one. Be sure to include your steam profile url, not name. Example will be below on another way to get access.
2 - Steam market currently has thousands up for sale for 2¢ , however the minimum steam wallet purchase is $5. You may find the market here on your primary steam window: http://puu.sh/208fo
3 - http://steamcommunity.com/id/dota2bot - This is how your steam profile link would look. You may right click on your profile page and select copy page url to get your own link as well. Also instructions on how to get and or give copies of the game are posted on that profile.
I would suggest your extra DOTA 2's go on that bot due ease of access for others in obtaining the game.
4 - http://www.dota2.com/survey/experience/ - You may use this for a chance to get in. However I highly recommend using one of the other above methods as you will not have to wait to play.
--- NEW PLAYER INFORMATION ---
Websites and Guides -
http://blog.dota2.com/ - The game's official website.
http://www.purgegamers.com/welcome-to-dota-you-suck - This is the general newbie guide that gets tossed around. Very informative, I suggesting looking at this before anything and read it all if you can.
http://www.cyborgmatt.com/ - This blog is handy for hearing about patches and what's in them. Matt datamines and analyzes content.
http://www.dotacinema.com/ - The site is still young, however it offers / will offer a nice choice as another hub for all things DOTA 2.
http://www.dota2wiki.com/wiki/Dota_2_Wiki - The game's wiki. Handy for learning what each hero can do and a list of in-game items. Also offers detailed information on recommended items for each hero.
- Youtube Channels -
http://www.youtube.com/user/DotaCinema - Dota Cinema's youtube, they have playlists of Hero previews/guides/game news/entertainment. I suggest subscribing.
http://www.youtube.com/user/purgegamers - Purge's youtube channel, he may not be the best of the best but his game play and commentaries are still informative to learn tidbits of heroes once you get the basics down.
--- FINAL NOTES ---
I'm no expert at topic making at all on GameFAQs in terms of layout and I'm quite sure I'm missing some valuable information, so I'll state someone else is more than welcome to make another topic.
However I wanted to make this in hopes of getting this topic or another, better one, pinned for new players to come to once visiting this board.
Thank you for stopping by and I'm open for suggestions/posts of what I missed/got wrong, however the time frame for editing a post is small. (unless an OP can edit stickied topics, do inform me!)