One of my worlds

[Midgardsormr]

I have a question though. Once I get to the stage where I add the cities and so on - do I just put a dot down with a label, or do I draw a funny little city?

You can do either. I generally prefer a simple dot, both because I find it more aesthetically pleasing and because it's far easier. Take a look through any dingbat fonts you have installed and see if there are some symbols you might like to use for cities and landmarks.

- Find out how to do the emblem things most maps have in the corner

Here's a breakdown of those sorts of things:
The compass rose is used to indicate which way is North (or whatever cardinal direction is most important in your world).
The scale bar, of course, is a measurement device, showing a standard distance in an appropriate length unit.
The legend is a guide to interpreting the symbols, colors, and textures on the map.
Any box or somesuch used to contain this or other information is known as a cartouche.