Ant 101 from a junior programmer:
I downloaded Ant from Jakarta and set the ANT_HOME variable and added ANT_HOME\bin to the path.
Then I started reading the documentation in the manual (\docs\manual\index.html). I took the build.xml example from the section Using Ant in the manual and started playing with it.
When it dawned on me how it worked, I kept adding more and more tasks. I was amazed at the power and speed of Ant.
The build.xml is basically a lists of tasks you CAN do (compile, copy, create a war file, etc.), combined with target directives which specify which tasks you WILL do with a particular target setting.
The first time I used Ant I just used someone else's build.xml and changed some variables. It did the job, but I did not really understand how it worked. The second time I built my own build file, and then I was able to do much more with it, because I had grasped the idea behind it.
Enjoy Ant! It can save you a lot of time.