@Alex FreeloveArms length is when you're complete strangers and have no business interests (like employer/employee).Non-arms length is like buying from a family member or someone a business interest.Non-arms length sales below market value can be scrutinized by the IRS for equity gift tax by the seller.On the opposite end of the spectrum, non-arms length transactions are also an issue if the seller is underwater on the mortgage.FHA also has some LTV limitations of 85 percent maximum for identity-of-interest transactions on principle residences.Friend to friend is probably a non issue,  but it could come up.

Can anyone recommend a reliable, honest, and effective property manager, who doesn't mind a mix of properties, some on the lower end?

While appreciation will occur long term, over the short term it isn't so reliable of a thing.

We're a new-ish player in town that's matched >1,000 Denver homeowners and investors with reliable local contractors. 

I would say one theme is to look at the owner's needs (is it income, security, a place to live, tax advantages, taking over a problem, a reliable buyer who can make monthly payments, etc).

The only reliable way to determine cap rates are when closed sales are analyzed by a third party in a consistent manner. 

Though keep in mind that no two lots are identical and you'll have to adjust for the tangible differences and the intangibles.The other way to do it is to determine the lot's "highest and best use," and then work backwards from the ultimate value of the property given its highest and best use, subtracting out the hard costs, the soft costs, the builder's desired profit, etc. 

I would like to build a network of reliable and trustworthy individuals that are in any way shape or form involved in real estate - investors, agents, brokers, lenders, CPA's, tax attorney's, financial advisors, property managers, insurance agents etc...I currently have 1 rental property and my goal is to expand into a comprehensive portfolio in the Boulder, Denver and Summit County markets!

I am looking for a reliable general contractor in the Pittsburgh area for some rehab work.Any recommendations?

Craigslist is not always reliable; Many rentals advertised there are owned by mom and pop landlord types who may not have researched current market rent and so their property may be priced below market.