Requirements to sell investments in other people's syndications?

[Graham Lutz]

Let's say, for instance, I have a bunch of connections with groups doing syndication deals and I have a bunch of interested investors.  What are the legal requirements for me to make fees or commissions off of bringing investors into other's syndication deals? 

I've done lots of googling and found mostly info as it relates to stocks, etc.  But, hypothetically speaking, if one wanted to build a business around this idea, how can that be done legally? Obviously, talking to a lawyer will be necessary before actually moving forward, but I'd love to get some high-levels answers first if possible.