Even if you're an equal partner with someone, treat it in the same manner as you would with hiring an employee.
Ask for a resume and portfolio of anyone you want to work with. Seriously! That lets you see and verify what kind of skills they have. And you should give them yours as well.
Check out any public social media pages they have, twitter, facebook, tumblr, personal or company websites, etc.
If you'd like to dig deeper, if they've done any past collaboration projects you can contact people the people they worked with and ask about them.
As for the trial and error thing, yeah, that's inevitable regardless. A good way to hedge your bets is to not have too ambitious a first project with a new team. Start with something smaller and shorter while you get used to working together, and also you lose less if things don't quite work out.
And ALWAYS, ALWAYS, ALWAYS, have a contract, especially if money will ever become involved. Make sure it spells out what everyone's duties are, who retains the copyrights to project assets and IP, how any profits and expenses will be divided, etc. Even if it never needs to be enforced, working out the contract itself is basically a pre-negotiation for any disagreements you might have later, so it settles all that junk ahead of time so you can better focus on just getting stuff done.