Searching custom fields

Hi,
How do I build a custom form for users to enter criteria and search a specific table? I can build a form and save ok, just don’t know how to point the form to a specific table!

fyi I used Formbuilder to create a form for entry (what table does this save to by the way?); now I want to be able to give people the ability to search that stored data, or search on another table – is there an addin anyone can recommend? I’m a beginner…

Any help appreciated!!!