I wonder what I can use to track the ceiling that is below the roof to catch a leak before it becomes a major issue. 

And track your expenses!

For market prices, 2-4 unit properties are primarily listed on the MLS, so you can search that, or realtors have better comp tracking you can utilize if working with a realtor.As for rents, look around on Zillow, Craigslist, MLS. 

You have found the right place to learn and make some $$$, most important for Private Lending is your track record so be prepared to bring some more cash into your first few deals with you.

There are two components of management for you to consider: onsite and offsite management.As it relates to onsite management, the common and most generic strategy is to interview the existing tenants to find a capable, trustworthy, willing resident to be your manager.

Being that mortgage rates tend to track 10 year Treasuries, you should call your banker today to see if it makes sense to lock in a low rate on your primary residence.

I know my capabilities.

@Joe Lui the letter should be fine and typically certified mail is better in these scenarios to ensure it is delivered or at least a tracking #.  

Factor the worst case in every investment and you should be on track to make the HELOC work in your favor. 

What kind of rehab are you capable or doing?