I'm really sorry if this is a Newbie McNew question , but i'm finding that there's more to meets the eye with this cartography lark !!!

I imagine that to make a map look realistic, landmarks and ranges of things should be placed in particular places. I'm not saying that all mountains should be in the upper left, or anything that specific, but how to you know where to locate your mountain ranges so that they are geologically believable??

For that matter, rivers, lakes, marshes, forests I would guess need some sort of elements to be present to develop over time. I'm no brain at this sort of thing, as you can probably tell, but I'm guessing mountains don't just grow where they feel like it, the same would be for rivers etc., (am i being to simplistic?? seriously, this is all really new for me)

What about towns and citites, they don't just spring out of anywhere, just for the nice view, shouldn't there be a reason for them being there?? (I'm guessing fresh water would be a starting point).

I guess my question in a nutshell is, how do you know where to put all these things to give your map of an imaginary continent/country/world some believability??

Apologies if these questions cause alarm , i'm sure they're obvious or at least easy if you think about them, but, as I said, this is all a very new area for me.

Thanks in advance,