Some volumes by Brasselet (ed)
Giraud: Etudes locale des singularites. 1971-1972. Course notes on lots of things related to resolution, in particular in char p.
Greuel et al: Introduction to Singularities and Deformations (Springer Monographs in Mathematics)
http://mathoverflow.net/questions/38237/singularities-of-space-curves-open-question-lists
Singularities folder under Geometry.
nLab page on Singularities