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.