DNNCreative.com has two applications tutorials by Paul Deschenes. These two tutorials alone are worth a one year subscription cost.
I'm not affiliated with dnncreative but have subscribed for several years and found these two tutorials the very best for OWS (no withstanding this forum and tutorials on this site).
How to Build Module Interfaces with OWS (six part series) (aka Building a Knowledge Base with OWS)
Form Validation, Dependant Drop Downs, Data Level Security in OWS (aka Car Parts Application with OWS)
These two tutorials will cover almost every basic function and feature you will ever use in OWS including getting a subset of data from your database, determining who has permissions to view different subsets and exporting results to word and excel.
PS: The car parts will get right to the meat of your question the quickest.