Consequences could be disastrous Keep everything professional, this sets the tone for the tenantBookkeeping and Taxes If you do it wrong, you’ll end up in jail You can use spreadsheets by dividing it into sections that correspond with the IRS’s categories for income and expense You can also use QuickBooks.

There are numerous ways that you can lock up or control a property if you find one that you want before you are ready to sell. 

The king in the category is clearly the internal rate of return (IRR) which takes into account cash flow, appreciation, debt repayment, leverage, etc. over the life of the investment.

@Tyler Darby I would suggest you break out your expenses into two categories: operating expenses and debt service.

As to your questions regarding whether you should seek out a CPA, yes, you absolutely should, but legal entities are generally more the realm of an attorney as California does not allow the "unauthorized practice of law" and drafting an operating agreement likely falls in that category if done by a CPA. 

There is not a pre-foreclosure category in Real Estate. 

What would everyone consider fundamental categories of things to learn about in real estate?

This depends on numerous factors including the local market, the existing condition, the cost of upgrade, etc. 

@Tammy SkeathI use a scoring system that addresses the following categories.  

Of course, there are numerous scenarios and negotiation tactics that can alter this.