This technique works best for someone with a good job and lousy credit (can't get a conventional mortgage).  

What is the best route to ensure that our money is backed/secured - promissory note and mortgate?

Any thoughts would be appreciated.Thank you,SteveIf there are multiple secured liens on the house, it depends on who is foreclosing. 

My question is should I make my offer and worry about getting financing later or secure pre-approval first?

With market rents, coming up with first/last/security deposit can approach $10k in some neighborhoods, which can be a difficult check to write even for professionals.

I have a few people family included, possibly even my doctor lol that have come to me and brought up the fact that they would like to invest in my business. We're in the beginning stages of discussions. Now I know it ...

I have always been interested in real estate investing, but the security of full time employment & raising my family took priority.

The Mortgage (or deed of trust in some states) is the legal instrument which secures the property as collateral for the loan.It is important to think of it in those terms as they have two different purposes.

And what are the best things to look for to buy a house under market value to secure equity?

Since the security deposit would be paid to both Parent and Child, and the parent is just staying - what kind of special language do I use to say that the security deposit is being transferred to new lease - but in addition when it is returned it will be made payable to "parent AND child" since they both submitted it?