I agree that cities in general are harder to do as a beginner, but there is a great tutorial here (http://www.cartographersguild.com/...ead.php?t=1150) that starts with a randomly generated village or small town. It is in Photoshop so it should be quite helpful in that regard, but I am not sure if the generator is still available (think it is but you never know).

Once you walk through that I would suggest (like the others) doing a larger regional scale map containing the area around the village and city (plenty of tuts for that too) before going for the big city

Anyhoot, start with something and post as you go and let the comments flow. Before long, you will have maps that will blow ppl away.