I guess there's two (overlapping) aspects to it, the first is the road pattern and the second is the style you use to draw the roads (black and white / colour etc).

In terms of road patterns, the best way (as Neon alluded to) is to study maps of places like the one you wish to draw and try to look for underlying rules so you can get a similar pattern. Ask yourself why some roads are straight and others twisty. Look in particular at the density of the road network.

In terms of style, think hard before you start about the relative size of the roads to the buildings. If you look at a street atlas, the roads are hugely oversized in scale so that they are clearer to see on the map, at the expense of space taken up by buildings. You need to judge how much clarity / emphasis you want to give your roads.
Take a look at 'the creation and depiction of fantasy cities' link in my sig - it may give you some ideas.

cheers

Ravs