I've only been flight instructing for a short time now, but I haven't had much expereince with VDP's or decent planning. I've heard people talk about things like the 6/3 rule and whatnot but they never elaborate on exactly what that means. I'm wondering two things, and so I understand I'll use specific situations: How would I calulate a VDP for both time and distance if the TDZ elevation is 750 feet? Second, if I'm at FL240 and have to get down to 10,000 feet, how do I know when to start the decent and what decent rate to use? How about for a 3 degree glide slope? I know this stuff is probably common sense for many of you but I simply have not really had to work with it much.

Also, does anyone know what brown diamonds along an airway means on a jepp chart?