The following is a list of resources that might be helpful for CSIRT teams.

Trusted Introducer maintains a list of de-facto standards for CSIRTs, PSIRTs and other security teams.  This includes:

Working Groups

TF-CSIRT runs a number of working groups.  Find out more here.

Training Materials

In addition to TRANSITS training, TF-CSIRT has a list of recommended training sources for CSIRT teams.