How should I structure this partnership? My father has about 1 Million in different properties he purchased over 10 to 15 years ago. Some of that land has doubled or tripled and some he is even. The properties are ...

It's a hub for shipping having the port in Long Beach, etc.

They are free with just the cost of shipping at www.vistaprint.com, and some other sites.

They don't offer all b&W, but they're charging $188.88 ($150.97+$37.91 Ground) for:5000 postcardsColor front / b&w back with matte finishFree email proofsProduction time of 4-6 business daysGround shipping (2-4 days)Locally, you might try  AlphaGraphics for high quality products and services.

I will definitely check them out and see how they compare with shipping charges, etc.  

So far we have created successful Craigslist ads, began networking at local real estate meet ups, cruised for cash in various areas in Baltimore and the surrounding counties, done research on potential homes and spoken with sellers.

It has army bases, huge shipping port and lots of economic activity that is strong.

Or is this just the tip of the iceberg and I'm looking to hit something that could sink my ship?

I have used bestonlinecabinets.com for multiple projects great real wood quality and fairly easy assembly and good support as well as direct shipping usually included for a full remodel. 

Heck, just go on a cruise and watch for similar sales 101 techniques used to up sell shore excursions, on-ship "exclusives," or on-shore VIP jewelry retailers (aka retailers the cruise line gets a kickback on).