@Vlad Krokhmal and @Ben Beddick our real estate brokerage firm Wayfinder Homes specializes in working with real estate investors.

I don't know much about raw land but I would think that you reach out to 2 or 3 agents or brokers that specialize in land sales and get their advise.

I would put that extra 100k in CD's, bonds and an s & p index fund and continue to add to it. 

We are a few friends with special needs kids, who want to book and buy houses adjacent to each other.

There are some bond programs both county and state level that you can get the downpayment and some closing costs paid or go new construction and do the same via the builder.

Do you know of any service or lawyers that specialize in rental contracts?

If you play with a free trial of Property Management Software (Appfolio Buildium Propertyware) you will have a great idea of what to expect and what you need to learn once you access Yardi.I would suggest you go ahead and apply for the job or start as a temp for a company that specializes in placing property management workers.

Out of courtesy and necessity to our investor clients we keep a handy investor focused lender cheat sheet categorized by mortgage specialities.

If I did it, and I'm no one special, anyone can do it.  

Probably not as easy as that as you still need some income to support some of the properties perhaps, but something to consider.It takes a special wife to be able to move often.