Drop command is easy to use. Grab vectorboson's drop command tut for starters. Next, grab one of the dialog drop generators from the script section, and use it to get the hang of how the particles look. But when it gets right down to it, it takes a lot of trial and error to get a good looking drop.
Dialogs are more complicated, and I don't know them that well, but they aren't impossible. Grab vectorboson's dialog tut and read it. Also, grab Razorwing's dialog generator, which will save you TONS of time in the whole trial and error phase when you are trying to get it to look just right. Then, start with simple dialogs, like a "confirm save" dialog for example.
Drop command: Did some experimenting with the drop command the last few days, and by now I'm actually able to create simple things, for example I just created a yellow smoke grenade for choppers to estimate the wind direction, based on a script by Babalon.
Dialogs: No advance here, this is too complicated, much more than "just" learning the 15 parameters of one command ;D. Thanks for the advise, I have downloaded the dialog generator and will start maybe on weekend.
ps: I finally managed to download your mission "Realistic Combat Patrol", will try it now (I have always problems when downloading from OFPEC). Your description sounds awesome