3. "Edit" then "Paste"? 

Let's see if this helps. Here's how I do it.
1.) select print screen via a key on my keyboard.
2.) switch over to paint program
3.) go to "Edit" and then "Copy"
4.) Edit it as needed through the Paint program
5.) Save the file as .jpeg (you must change this if you want to upload onto civfanatics. The default for paint is .bmp)
6.) go back to your game and have fun!
DOMINATRIX - First, sorry for the acronyms in my previous post. Second - I was wrong - using workers causes an attitude hit for you against the civ the worker comes from, not a rep hit. This article is the important one, though I'm sure there was an updated one for Conquests somewhere. I actually think that Conquests changed things so that using a captured worker for an airport or colony or disbanding them caused an attitude hit against you for every civ. I can't find that thread at the moment though.
For the acronyms-it's fine, you learn something every day.
For the article: that guy must have spent so much time on it, and how on earth did he learn that?
I occasionally see references from Civ-Assist II about switching to the "lone scientist" method for researching techs. Can someone fill me in on what that is?
Anway, here goes:
1) When you get to the point where you want to post your screenshot, hit the Easy Upload Button. It is the red button at the upper right corner of the posting box:
2) A box will pop up for you to find the file that you want to upload. Browse and select the file, and hit "Upload File."
3) When the file's done uploading, towards the bottom of the pop-up box, you'll see something like "Copy this code for your posts." (Wording may not be exact.)
4) Highlight and copy the code.
5) Close that box.
6) Now you should be back at your post.
7) Across the top of the bar, find the "Insert Image" button.
8) Click it.
9) A box will pop up with a spot to put in the code that you copied. Hitting <Ctrl-V> will paste the code in the box.
10) Hit "OK"
11) If you're not sure you did it right, hit "Preview Post" to check it.
Hope this helps.