Hello Cartographers!

I'm new here, actually I just discovered this existed, and I'm hoping you can give me a bit of assistance. I'm looking to do a map such as http://www.keanz.net/images/Auckland...l_City_Map.gif (a top-down perspective on a city) but I'm really not sure how to start. Should I draw it on paper first, and how should I do that?

I own Photoshop CS4 and Paint.NET, if that's helpful at all. Also, I'd appreciate it if any of you could link me to a tutorial on making a map like that.