Currently I'm thinking about offering both debt and equity styles of investments, so I would like to find out the legal documents and procedures in setting up such structure.

I decided to live at home after graduating this past December to pay off all "frivolous" debt, Ie credit cards and such from college.

@Eric JamesYes, when an IRA uses leverage, there are higher down payment requirements and the income to the IRA is subject to a small tax known as UDFI (Unrelated Debt-Financed Income).As such, using a mortgage in an IRA is different than using a mortgage personally, but that is not really the point.The thing to keep in mind when evaluating an investment with an IRA is how something such as purchasing an income property for the IRA using a mortgage might compare with investing the IRA in a property all cash, investing the IRA in a note, or investing the IRA in conventional financial products.The use of leverage such as a mortgage can boost the cash-on-cash return of the IRA, which is a good thing.  

HOA debts are the wild card though, that a title search won't necessarily help with.

However, if the place is operating as a rooming house - legal or not - when the appraiser reports back that there are 6 bedrooms (each with their own locks) and separate leases for each of the tenants, the lender will run away.Additionally, what @Ned Carey indicated about debt service not being included in NOI holds the same as practiced by investors in Canada.  

As your buying rental and your debt ration is your current Piti and what negative rental from the property your buying after calculation of thr piti & 25% for operating expense from 75% of potential income. 

Say, on a $300k building, should I be raising $100k from partners then get bank financing for the rest, OR raise the full $300k then refi in 2-3 years after building stabilizes?

If the loan is set up amortize for the 30 year on 500k then the refi, debt service is only going to be approx 2k monthly.

My current interests include fixing and flipping houses and restoring historic properties.

The law does not outline such specifics and there is little case law to rely on.We would definitely not recommend that you JV with your IRA while obtaining debt-financing personally.