Using Yahoo Maps isn't hard. To be perfectly honest though, I'd say that Google Maps has better documentation and seems to be snappier. However, Yahoo has a Flash option that works well. In this page, we'll focus only on the Yahoo Maps Ajax interface.
Yahoo Maps Ajax Interface is quite similar to Google's, and easy to use.
There are a lot of things you can do on Yahoo Maps that are pretty similar to Google Maps. For example, we can do something really easy, like adding a marker, which I'll illustrate below.
The first thing you'll be interested in is how to size the map. This can be done via some simple css. In my example, I have an id selector for the map named "mapcontainer". Notice that there is an inline style tag in this file because I'm lazy. Obviously, you'd put that in seperate css file. By simply defining the width and height attributes of my id selector, I change the size of the map.
#mapcontainer{
width:400px;
height:400px;
}