SharePoint 2010 Development Project- Design Pattern

I am designing a simple project where 20 custom SharePoint lists and 10 documents libraries are there. UI (to display, update, insert, delete data) will be fully customized and no OOTB UI/functionality will be used at all.

I am planning to custom page layout/web part pages, visual web part to display and commit data to doc lib or lists.

can anyone guide me whats the SharePoint standard custom development patter using visual studio?

What should be visual studio project structure? Shall I use any design pattern compatible with SharePoint 2010?

If I create a helper class where common methods will be there and those will be calling from UI. the most simplest way to do this. 

Please suggest..

thanksArup MCTS - SharePoint

Play Sudoku Online