A slow reply as I had never seen this item, but I figure to answer because others may have the same question.
You will find the books limited on share, the wrok book is about the best, but it is still very very limited in the area of share, but its a places to start.
I found the startup learning curve because of this to be higher then expected, but you will find once you get a handle on the framework it's a bit easyer.
I run using eclipse in the following way, others my have better methods.
I have an apache front end with a mod-sk to allow it to work with tomcat.
I have a deploy script that will move my webscripts to the share folder under tomcat.
the Javascript I modify are under Apache and don't need to be moved.
it would be better to run it all under eclipse so you can start and debug within eclipse but I have not done that yet as I expect it might take me about 3-4 days to figure it all out as I have several alfrescos on my machine 3.3.3 and 3.4.0 one modified and one out of the box so I can see when my change bollixed the thing up.
all the share parts your going to twek will be in /tomcat/webapps/share/web-inf/classes/alfresco/
you can change it here and restart, but that's not the correct way to do it.
copy the file to
tomcat/shared/classes/alfresco/ restart
after the first time you can change and you don't need to restart, just do share/service/index and refresh the scripts.
Hope that help.
hope others will tag on to this with better ideas, because we could all use a hand.