@Will Grabert,Rents can definitely recede for a variety of reasons, e.g. major employer leaves, over supply being built, 2008.

There are a variety of ways to do it.

I really appreciate getting the variety of people's opinions.

You may get a few dead leads and unqualified people but how many can depend on a variety of things (location, rent amount, listing description, etc.).To effectively screen prospective tenants, you can/should ask for W-2 forms, recent pay stubs, employment verification, landlord referral letters, and conduct a background check on them as well.

So I'm just starting out attempting wholesaling and I'm going to attempt mailers to a variety of property owners and I have a couple questions.

You have to use a variety of approaches combined with your own knowledge, skills, and abilities, to figure out what the park is worth and what value you can add. 

The more established the better, I might also recommend things that aren't designed exclusively for rent and are designed for a wide variety of C2C B2C and C2B payments more along the lines of Zelle etc.

There have been a variety of strategies offered up and discussed in great detail on BP threads and forums, mine included, with regards to the strategy one would employ investing in A/B class properties versus C/D class properties, or TK vs DIY, 1% vs COC returns vs IRR vs ROI, etc etc, I think the most important thing I've learned is that each investor should define their goals, financial situation, risk aversion, willingness to be hands on, etc and identify what the best strategy is for them to meet those goals, and DO YOUR DUE DILIGENCE, and NEVER WAIVER on your metrics of evaluation.

Not sure how to offer "fresh" items like milk or bakery muffins if I can't have them in a supply closet for the maids to put out after a cleaning...I am putting a Keurig in and planning to offer a variety of coffee, tea, and hot cocoa pods and some shelf-stable half and half or creamers.

You'll find them a variety of ways: expired listings, landlords who have filed for eviction, probate sellers, pre-foreclosures, and as referrals from active agents, just to name a few methods.