There are a number of different patterns that can be found on the internet by simply using google. Here is a pattern that is pretty easy to follow:
This is from a group that are also crocheting for the same cause. They have a lot of different patterns. PLEASE REMEMBER that all love caps should be crocheted without any big/loose holes!
Also, youtube provides some very helpful tutorials on hat making. Check it out!
Here is a link to a youtube channel that is very helpful. http://www.youtube.com/user/tjw1963
Take a look at her tutorials on hats.
Here are some more patterns: