Create a custom view, and add a custom sortable column I want create a view for display a list of contents. (same type)
(its my first fully custom view x) )

I want display the view like this : 

//form : the user select a Date field, its an exposed filter field

COLUMN1           COLUMN2_sortable
-----------------------------------
content_title0    "special_value0"
content_title1    "special_value1"
content_title2    "special_value2"
...
content_titleN    "special_valueN"


First, can you tell me a good web tutorial for learn to create a fully custom view (so, create the user select form (contain exopsed filter) , the content of the view). After several google search, I difficulty finding a good guide...

Second, the COLUMN2_sortable contain a integer data. And this data is calculed via an another custom module (this value depends on the date entered in the exposed filter field). I have no ideas how add a custom column (here, the COLUMN2_sortable) in my view.
Because this is my first try in fully creating of view, can you advise me about the good way for implement that ?
You can make a column sortable by clicking on your type of view "fields" and check the "make sortable" checkbox.