Some places (Ohio and Michigan come to mind) are notoriously fussy about doing anything like that without a license.

I once went tracking for 30 days and managed not to get them until the last night...I was worried for weeks as they are notoriously difficult to get rid of.  

South Florida is notorious for strict condo regulations. 

As for where to invest, I just went with the areas I knew really well- though CA is notoriously expensive to buy, the rental rates make a decent supplement to my income, especially while I stay overseas. 

The estimate was $27,000.I found out that block was notorious with foundation issues and I passed because I didn't want to face the same issues in 15-20 years.

Big piles of snow will limit how many people want to come out and check out the property and the holidays are notoriously slower than the summer months since buyers' minds are preoccupied.

I can absolutely attest to the fact that you should consider some type of alarm or auto close doors to the garage and the sliders to the pool area. guests notoriously will leave these wide open which will kill your a/c trying to keep up.

In three deckers, the most notorious/expensive areas are as follows:-Exterior (if it's painted and chipping, no good. if it's vinyl, you're golden)-Back Hallways (these are the lead havens in three deckers. $5000-$8000 all-in for full three decker de-leading on all three back porches.)

They are notoriously difficult to find - at least a good one.

College students are notorious for abusing a rental more than others, so you would need to account for that in your monthly maintenance allowance.