This month we did a live demonstration of upgrading the firmware on an iDRAC of version 8 and version 9. Sadly I wasn't able to make videos for this one, but here are Dell's official walkthrough videos: (Please keep in mind RSA only supports certain firmware versions that can be found here RSA NetWitness Availability of BIOS & iDRAC Firmware Updates)
iDRAC9 Firmware Upgrade | iDRAC8 Firmware Upgrade
Dell has multiple guides on IPMI-based interfacing with iDRACs, which can all be found on Dell's website depending on your firmware and hardware versions.
The recording of the May webinar is available here:
Access Password: 8V*6.vT@
PowerPoint is attached.