The two (actually three) resources that I'm posting here aren't actually about cartography. But since 99% of the maps here at the guild are of imaginary lands, they concern everyone who is doing that kind of stuff...

So you draw your landshape, and you carefuly or not place your climate zones (your first map will surely have a desert at the bottom, a snowy region upwards, a spine of mountains that is almost impossible to cross and a few large rivers, likely violating a couple of laws of the natural world... then you get better at it, eventually)

Once you do this, you'll have to place cities, villages, castles, roads, whatnot! Your first map will have them evenly distributed... then you get better at it.

Here's an important thought about getting better at it:
- cities are about trade - they flourish where trade routes concentrate - and trade routes aren't random - that's because traders are "people" who "think" before they act - so trade routes will have some logic...

When I fist saw this webpage I went, "duh! obviously! well, that makes me reconsider all my maps, but hurray anyway!" and that's why I want to share it with your guys:
Archatlas: Trade
Archatlas: Portages
If you understand these "visual essays" then you're good to have 100% credible routes in you imaginary map.

But still, you can get a better understanding a how trade/transport works by playing about in a simulation for the roman era:
Orbis: traveling in the Roman Empire

And that's that, in a nutshell: don't draw roads and cities at random... there's better ways to do it.