Recommendations for courses, communities, coaches or resources?

Has anyone here taken any courses or worked with any business coaches that were absolutely integral to your success?

I've worked in tech for about a decade and co-founded a couple of successful companies but my new idea is more complex than anything I have tackled in the past. I think I need a little extra help thinking through my overall model and plan of attack.

Does anyone here have experience working with someone who gave them that extra oomph and made them successful? If so, I'd love to hear your experience.

Thanks in advance.