Question
Ideas I'm considering:
-more guest blog posts (SPECIFIC suggestions welcome!)
-webinars (I've done a webinar with the Project Management Institute in Nov 2014 and have another in the works; who else can I do a webinar with?)
Website Founded: June 2014
Current Email Subscribers (with Aweber): 141
Landing Page For Email List: http://projectmanagementhacks.com/SponsorReport
Guest Blog Posts published in 2014: over 50 (full listing here: http://projectmanagementhacks.com/portfolio/
Answer
I'm with Mario on considering a big of a redesign to convey a little more trust and authority. Might seem like a big investment now but it's totally worth it.
In terms of growth though, free reports (PDF downloads), and webinars are a great growth strategy.
In 2003 for example we launched this site with 5 PDF reports, and 3 audio interviews (case studies): http://www.agentpress.com. We got 3,000 subscribers in about 1.5 months.
Try pop-up domination, design a good opt-in and offer the free report as an incentive.