Physicians are notoriously slow to adopt social media - especially as most Colleges and medical associations produce guidelines saying that they should not be interacting with their own patients online - see example http://www.cma.ca/advocacy/social-media-canadian-physicians. A recent survey I saw had Facebook use among physicians was at only 18%. It's very similar for Linkedin and let's not even discuss Twitter.
Best way to get to them would be medical conferences and journals.
I would suggest you consider it that is a good channel for you even if you reach them. If your baby food has a medical benefit, than pediatricians may recommend it, but otherwise we usually don't discuss brands with patients.

Anything from Steve Blank - and most of it is online - not in a book (yet!). Specific to competitive advantage, here is an Inc article about Steve Blank's new way to assess competition if you are just starting up: http://www.inc.com/steve-blank/a-new-way-to-look-at-competition.html

Great question - if you are spending the time and money, might as well make it super useful! Love the emphasis you did on "meaningful" - to me that is only achieved if you "rapid fail" a number of interactions that are not, so you have a chance to get to people who are the ones you can engage with. This can be best accomplished by creating a large enough volume of interactions and then pursuing the most useful ones:
1. As soon as you are thinking of going, post on LinkedIn and Twitter (and maybe Facebook depending on whether you are using it work-related or not) - say you are thinking of going and ask if anyone else is. Several days later, post again and ask has anyone been in past years, and what did they think. Then post again, to tell folks you are signed up to go. Don't worry, this is not spamming - as most people miss most posts, you will be lucky to have a few replies.
2. Also check Reddit and Quora - similar approach - esp if you are in Tech.
3. Before attending, use the Twitter hashtag and share your excitement to attend, questions you would have for given topics or speakers and add their @name - many actually reply! Make yourself a Twitter list for the event.
4. At the conference, continue to engage on Twitter. If they have a conference app such as Bizzabo, register and see who else is at the event.
5. "Speed date" networking: When waiting in line at the lunch or sitting down with strangers, ask not about the weather, but state something new you have learned at the conference, and ask them what is their take away. If nothing meaningful, wish them a great conference and move on till you find someone who gives you an interesting answer - then engage.
6. Sometimes I use clothing/bag to engage - as I am a Canadian - a logo from my home town and country usually gets folks to approach me and start a conversation (one of which by the way led to an impromptu memorable chat with Biz Stone). A T-shirt from a given tech tool /company I use also gets like-minded people to reach out.
7. Last but not least, at the event, smile and have fun, and go for what you feel like doing. One of my best work connections was made when I skipped a session at the SalesForce Conference in SF and instead played in the conference provided giant chess in the sun outside. Things happen in mysterious ways, so follow the force!
And congrats for being selected for the WWDC14... I hear it's not a given. ;)

If you have the information needed for the infographic, one of the things we have done is hire a few people from Fiverr to do one. This quickly and inexpensively gives us ideas about what we like and also allows us to test it - see how people respond. Then you can go for the greater expense of having it done high res or print quality.

Sometimes a large company can't make money by offering more add-on services, but they can offer more services (not minor features) to customers from a partner/outside provider. This gives them two advantages - retain customers this way and make some money through a shared service deal with the smaller service provider. So if your idea could be suitable for something like this, you can present this idea as the possibility of becoming the partner to them. This only works if you have the credibility and you can actually build it out and make it work. They can sometimes even fund you to develop this. Always the danger that they "steal it", or more likely, don't get excited about it (probably because it's on their internal list of things they thought of, but can't get to).

Have been thinking about this for a while.. The answer that follows is based on insights I got from a panel in SF and from discussions with my co-founder Rob Attwell. So why is Silicon Valley/SF the birthplace of most great tech companies? It's about the unique concentration of 5 Cs:
1. Coders (esp with experience)
2. Concepts (new ways of solving things that end up in SV/SF because everywhere else they are deemed crazy)
3. Customers (willing to try things and with disposable income)
4. Cash (investment)
5. Competition (essential to keep you going faster and higher)