I am currently transitioning between tenants where Tenant A (moving out after 2 years with no issues) referred and is the sibling of Tenant B.

Most people who think they want to do both, as soon as they get into this for a little while, find out that this is pretty hard work if you're not going to reap any reward.

A good attorney or title company should be able to refer a quality broker. 

Are you referring to the Market Finder tool or the classifieds section where you can post asks and offers for real estate services?

I think of finding rental comps as basically the same process as finding purchase comps to reference. 

Its better if you get a property managers phone number because you can cross reference that with what is listed on their website. 

@Thomas SehonRecommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

I was not impressed as they would not provide any references for reviews, they sited privacy concerns, which I thought was unusual. 

Oregon has capped rent increases at 7% + CPI (10%) max for future reference as well. 

The second reference, Publication 523, gives 2 key bits of information that I've never seen anywhere else, and certainly not on Section 121 itself.