Over the last few days I've been reviewing Juniper's free training material titled "JUNOS as a Second Language." This was released a while back as part of a Juniper certification promotion, but I've only recently gotten around to watching it.
What Juniper has done here is pretty clever: the training capitalizes on its audience's existing knowledge of Cisco IOS syntax in order to teach its own operating system methodology. This is quite beneficial to engineer with Cisco experience, as it saves time spent weeding through "this is a packet" introductory material to find the new stuff.
The presentation itself exists as a semi-interactive Flash video, which in my opinion has been designed very well. The outline is easy to follow and the narrative is natural and engaging (no small feat considering the material).
Even if you've never touched a piece of Juniper gear (as I haven't), I still recommend at least the first few sections of this training. If nothing else it provides some decent exposure to the JUNOS command line, and hey, it's free. It's also kind of funny to hear the subtle jabs at IOS now and then.