I receive a w-2 and 10-99's at the end of the year.I am trying to figure out how I can stock pile cash that can grow tax free AND be used as collateral to purchase more Real Estate. 

Without experience and collateral, banks are less than willing to talk in the beginning. 

@Jasmine Cotes  its often thought on BP that he very best way to start is to buy a 4 plex in a great area with your FHA loan... this allows you the low downpayment as for reserves and such you simply need to talk to your mortgage lender but yes you will need some.I believe you can only have one FHA loan in your name at a time.. so the idea is you would refinance this 4 plex using its current equity if any as your collateral.. the you could buy another one with the FHA loan rinse repeat.you must live in the property for at least one year. 

I will 2nd that -- While FNMA will hold you to 10 units financed...Commercial Portfolio lenders like small banks in WA will do a 80% LTV portfolio loan holding multiple properties cross collateralized with yields under 5.25% and no prepays or junk fees.

You might use a lien, but if you can't own, what good would the collateral be if you can't accept title?

As long as the person lending the funds is not a party to the sale, the terms of the loan are documented along with the collateral, and there is evidence of your receipt of those funds.Again, make sure you are working with an experienced loan officer that can help you navigate the guidelines, to avoid any missteps.

This is a change in collateral, so what will the bank need?  

I am welling to put up some of my properties for collateral and give a personal guarantee.

You can  try to structure using collateral on your other properties but that might be harder to get.

In my experience, when a single lender is used for assets in multiple series then cross collateralization becomes an issue).