I'm most interested in learning how to do "Subject to" deals with little or no money and without using credit.

Here in CT good places to check for rental comps are:Craigslist (be sure the active comps are in the subject property's areaZillow (check the active places for rent and use the map to see how close it is to the subject property)

As @Zach Mitchell mentioned above you certainly could get an actual appraisal performed on the property  however unless you have it under contract just review the comparables that resemble subject project and have sold in the last 6 months. 

I think 5 is a bit much, but I have done all cash and a subject to financing offer before.  

Whatever you do, I would suggest running it by your attorney as I am NOT an attorney and this is simply my opinion on the subject.

@Stephanie DobbsIn Maryland you can look at buying on owner financing which could be subject to existing financing or wraparound mortgage

Well, if you are still within your "subject to" time on your offer, you have every right to back out of the individual deal.  

Hard money/Private lenders typically do a 65% LTV on the subject property.

Many simply shoot for a yield, a blind shot blindfolded, but the discount represents the risk assumed that places the subject investment in line with similar investment alternatives that carry different levels of risk, it is a risk based analysis.

If not .....When you post: Take the time to choose the correct forum to post in (Many forums such as Marketplace and Investor Deal Diaries instruct members on posting in them)Make your subject line direct, and relevant to the post, that is what draws people inBe specific, ask yourself, if you were reading would you know what the poster was wanting, or talking about?