It means running lots of numbers on rental income(not just using pro forma rents) and projected expenses(does the house need a new roof soon?).

The pro forma rents are pretty easy to figure out in a primary market like CO, but understanding what expenses you pay can be tricky. 

Unfortunately the save function is not yet available on the Vrolio pro forma, but investors find that taking a screen shot of their spreadsheet is helpful.  

Why are you looking to form a group - Are there qualities that you are looking for in a partner?

I would encourage you to think a little bit bigger, and rather than looking for an internship see if you can join or form a team/partnership. 

That is what excites me.THE ASK: I am looking for recommendations to learn the basics of a developer (critical questions to answer, due diligence, pro forma, site planning..). 

Just to add and maybe clarify: most sellers are selling not on actual, in place income, but on potential or pro-forma income.

You can put whatever you wish in a contract form. As

I am planning to begin real estate investing by forming a partnership with a family member - my brother in law.Neither of us has established an LLC for these purposes yet.I am trying to decide which would be better:1) for us each to form our own LLC individually, where one is the owner and the other an investor, or 2) we form a single LLC as partners.I would love to hear thoughts on potential pros and cons of each, or possibly other alternatives.

I believe homeowners and investors alike have walked away from more...yes, since you are investing with a non-spousal partner you should form a company of some sort, most would use a LLC.