For my typical reports:
[Dropbox installed]
ALT-PRTSCRN at pertinent moments
[Finish Playing]
Move all the pictures to a subfolder in my Public Dropbox folder
Use
Bulk Image Converter to change them all to jpegs (mine save as 1meg png's for some reason)
Rename all as [a number][a name], e.g. 200Overview. The number helps sort them by session (more relevent in PBEM/SG than Tournaments, but still). Note that this is multiple screenshots bearing the same name, so you'll end up with a bunch with names like
200Overview (1) and
200Overview (16)
Copy Public Link, paste into a blank post box.
Wrap [screenshot ] [/ screenshot] tags around it, copy with wrap.
Paste as many times as I have screenshots with the same name.
Write report, renaming them as I go along to fit the proper narrative.
Long and possibly not applicable, but it's the sort of breakdown I would have appreciated when I started, as a lot of it is non-intuitive.
If you've been playing for a while, I suggest skipping some of the early games, as they're not aimed at someone used to the game as you. Potluck, for instance, is much less interesting if you've played all the civs before.