Smolin's book would be a natural place to look if you have the bucks.
However there is stuff online, for free.
especially if you are willing to read EXERPTS of longer articles. Like xeroxing just the 2 or 3 pages you need.
A German philosophy of science expert named Rüdiger Vaas did a critical study around 2002. I don't agree with Vaas, I think he points to weak points that actually are not there. But it is a careful study of some 30 pages with a long bibliography----i.e. it is scholarship. And it is free for download.
Smolin has some articles from around 1994 and 1995 on arxiv. they are free.
For me, the best source has been about 3-5 pages out of Smolin's 2004 essay---Scientific Alternatives to the Anthropic Principle. Also free, on arxiv.
I will get some links, maybe some other people have more sources.
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http://arxiv.org/abs/gr-qc/0205119
Is there a Darwinian Evolution of the Cosmos? - Some Comments on Lee Smolin's Theory of the Origin of Universes by Means of Natural Selection
Ruediger Vaas
20 pages; extended version of a contribution to the MicroCosmos - MacroCosmos conference in Aachen, Germany, September 2-5 1998; finished in late 1998 and published in the conference proceedings (this http URL)
Vaas asserts that Smolin does not have a falsifiable central claim. He is wrong. Smolin has a central claim that is falsifiable (challenge: you can't point to a small change in the parameters that would result in having more stars collapse to form black holes----if you can, that falsifies the claim that the parameters are at a local maximum)
Smolin makes his main falsifiable claim here, explicitly and rigorously, what he calles "statement S"
at the bottom of page 29 here:
http://arxiv.org/abs/hep-th/0407213
Scientific alternatives to the anthropic principle
Lee Smolin
Contribution to "Universe or Multiverse", ed. by Bernard Carr et. al., to be published by Cambridge University Press.
need to start reading at page 28 to get the definitions.
observational predictions (like a mass bound on neutron stars) are discussed starting page 30.
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some good news for the CNS idea was when Elsevier publishing house decided to do a HANDBOOK OF PHILOSOPHY OF PHYSICS and they chose GFR Ellis (a cosmologists and co-author of Hawking) to write a 70 page chapter on Philosophical Issues in Cosmology. His draft handbook chapter is online, and Smolin gets discussion on pages 41 and 46.
http://arxiv.org/abs/astro-ph/0602280
Issues in the Philosophy of Cosmology
George F. R. Ellis
To appear in the Handbook in Philosophy of Physics, Ed J Butterfield and J Earman (Elsevier, 2006).
that is something that happened this year that makes me think the right time for CNS may be coming
another thing is the growing impatience with the Anthropic Principle as reported e.g. by Sean Carroll (a prominent and with-it young cosmologist----I often disagree with him but he's a bellweather)
another thing is some talk from people connected with FQX (foundational questions institute) that makes me think they have CNS more on their minds, maybe not accepting it but taking trouble thinking about it, looking for serious reasons to reject (instead of halfbake trivial reasons people come up with when they arent thinking). so there is this gradual sea-change around the CNS idea