Expert Help Required - What do I do next?

Hey Folks,

Looking for some good advice from some of you old hats

I'm about to be selling a type of garment that helps with body-shaping and postoperative recovery. I've created a site and as I know just a little about on page SEO, I have thus far spent my time ensuring all pages have:

Relevant page titles and descriptions
Included videos
Lots of outbound links to authority sites
Pictures have ALT tags
Lots of internal linking
A good overall site and URL structure
If I'm missing any biggies regarding on-site stuff please tell me!

I've now written some first-hand experience guides on various operations (they are currently in PDF format ready to do something with)

I've also got my list of keywords from hours of research. I can write content to match but there are well over 100 long-tail keywords at the moment - all allegedly with google traffic between 50-3000 a month.

I'm also creating an infographic for my industry.

So here's my problem........ I don't know quite what to do next? I do have some specific questions I'm hoping you might help me with?

1) I understand the need for inbound links - but what are the best ways of achieving these in 2015? Guest blogs? Promoting info-graphics? PBN's? All of the above?? Are there good quality link-building service available out there?

2) Do I write a single article for all my variations of long-tail keywords - or do I write one article that covers 4-5 related keywords?

3) Regarding my surgery guides - Is it best to have these as pages of text or is it better to have them as a free download with an email capture for list building?

Any help much appreciated as I'm not sure which is the best way forward, so at the minute I'm making the age-old mistake of doing nothing.

Thanks guys

Trev