Why is DG stuff coming up everywhere?
http://ncatlab.org/nlab/show/differential+graded+objects+-+contents
http://ncatlab.org/nlab/show/motives+and+dg-categories
http://ncatlab.org/nlab/show/differential+graded+vector+space
http://mathoverflow.net/questions/37202/derived-algebraic-geometry-via-dg-rings
Lunts and Orlov: Uniqueness of enhancement for triang cats arXiv
For model structure on DG-algebras, see Gelfand and Manin: Methods of homological algebra, Chapter 5.
Hesselholt in K-theory handbook, p. 81: The derived category of abelian groups is a triangulated category and a smmetric monoidal category. A monoid for the tensor product is called a differential graded ring. If is a simplicial abelian group, write for the associated chain complex. If is a simplicial ring, then is a DG ring (details spelled out…). If is a commutative ring, then is a simplicial ring.
I think this is what I thinking of: http://www.math.univ-toulouse.fr/~toen/swisk.pdf but I haven’t actually read them myself. There might also be something else by Toen on his webpage.
Also, here is a thesis which looks good: http://people.math.jussieu.fr/~keller/TabuadaThese.pdf
Things by Keller: http://front.math.ucdavis.edu/0601.5185 and also http://www.numdam.org/item?id=ASENS_1994_4_27_1_63_0 both look useful to me.
Maybe there is something useful in Neeman’s chapter in the K-theory handbook vol 2, which might possibly be the same as this link: http://wwwmaths.anu.edu.au/~neeman/preprints/author.ps
nLab: dg-algebra and dg-category
nLab page on DG stuff