CALCULATED FIELDS and MEASURES in Advanced Reporting

Hello,

I’m new to the Jaspersoft community and looking for the best tutorial / how-to information related to creating and using CALCULATED FIELDS and MEASURES in Advanced Reporting Ad Hoc view Crosstabs or Ad Hoc view Tables. I’m a bit overwhelmed with all the information available on the website and not sure how to navigate the site’s many tabs / different channels to find what I need.