An excel mortgage calculator with some nice features (extra payments, interest-only, etc.)All of them are freely accessible on this page: https://www.biggerpockets.com/...

I do know someone that did it themselves and their pool had large vehicle access (versus bobcat size loads).  

They give you free access to comps so you don't have to pay for Airdna's paid version.

Or homes up for auction that no access to the inside was available where maybe someone snuck in a window to get a feel for the condition of the property.

The attorneys are known to the assessors and there is a lot of horse trading that the typical Joe Public doesn't get access to.I have done work on my building and have a 5 year tax abatement in a portion of the taxes.

I really like the alerts feature that can quickly guide you to current topics that may be of interest: http://www.biggerpockets.com/alertsThere are a few self-contained guides that you can access here: https://www.biggerpockets.com/guides

With the heloc route I was able to access more of my equity vs refinancing.

This is a great forum with very knowledgeable members that will help to guide you in the right directionThere are a few self-contained guides that you can access here: https://www.biggerpockets.com/guidesI really like the alerts feature that can quickly guide you to current topics that might interest you: http://www.biggerpockets.com/alerts

Finally, if you can't find what you're looking for, try the Bigger Pockets' FilePlace: https://www.biggerpockets.com/files It contains hundreds of files such as ebooks, checklists and spreadsheets for real estate investors.

The biggest lesson learned was I needed to get access to the lending institution's pay off amount.