I have also signed up to receive email alerts on houses that become available in the market.

The big thing is tying up your house to an unknown when you want to sell.Imagine if you signed a lease option in 2007 for 3yrs. 

I seem to get stuck trying to determine the cap rate in markets I am not too familiar with and was wondering if there was a source out there to look up? 

We are now in "search" mode, we have created various versions of our own Cash Flow calculators, Cash on Cash calculators and have determined our goals for what we would like the house to produce in order for it to be something we would like to consider.

How are commissions on commercial sales determined, does the Seller or Buyer or a combination of them pay commissions or is it just part of the offer negotiations?

Have you seen the house and determined a semi accurate rehab estimate, or is it just a guess?

They are pretty aggressive with their marketing - as soon as I signed up for a free account, I started getting e-mails about once a day telling me how much value I could get from a premium membership.

The other two units are renting for $1300 a month and they signed the lease agreement last January.  

@Nadine Russell: First think I would do or verify is determine how much you could rent it for. 

I know the type of marketing it requires to be in this game with lead gen tools, mailings and bandit signs, but I was more less confused on what contracts do they use?