Even though I spend most of my time on configuring the AX application there are times where I have to put my developer hat on to workout what might be going on or trying to design a new solution. This is one of the nice things about AX is that you can investigate the code so if you suspect a bug of perhaps trying to work out a data issue being able to debug the application is helpful.

This is a link to the main help topic on Debugging in Microsoft Dynamics AX 2012.

Working with the debuger

http://msdn.microsoft.com/en-us/library/aa569668.aspx

Debugging different types of AX components

http://msdn.microsoft.com/en-us/library/gg860898.aspx

There also some good blogs posts and recordings from conferences that you might find useful if you are learning this. Some of the links are to Partnersource/CustomerSource so you will need to login to view those.

https://mbs.microsoft.com/partnersource/northamerica/deployment/documentation/videos/Debugging%20Video

https://mbs.microsoft.com/partnersource/northamerica/deployment/documentation/videos/Debugging%20VideoTC11

https://mbs.microsoft.com/partnersource/northamerica/deployment/documentation/videos/Deploying%20and%20Debugging%20Managed%20Code%20Video

https://mbs.microsoft.com/partnersource/northamerica/deployment/documentation/videos/Enterprise%20Portal%20Debugging%20%20Video

https://mbs.microsoft.com/partnersource/northamerica/deployment/documentation/videos/Debug%20Security%20Settings%20%20Video

http://blogs.msdn.com/b/axsupport/archive/2012/06/04/debugging-services-in-ax-2012.aspx

http://community.dynamics.com/ax/b/mafsarkhan/archive/2011/05/30/how-to-debug-batch-jobs-and-service-operations-in-dynamics-ax-2012.aspx

http://blogs.msdn.com/b/x/archive/2009/06/25/step-by-step-checklist-for-debugging-batch-jobs-in-dynamics-ax.aspx

http://community.dynamics.com/ax/b/axdaily/archive/2011/05/13/debugging-managed-code-in-ax-2012.aspx

Cheers

Lachlan