You can refer to the step by step guide for OpenERP custom web development in the official docs.

I finally find how to display a record, and that is NOT in the OpenERP documentation ! Here is a simple function Javascript :

    openerp.test = function(openerp) {
      openerp.web.form.widgets.add('myWidget','openerp.web.form.myWidget');

    openerp.web.form.myWidget = openerp.web.form.Field.extend(
    {    

 start: function() {     
       this.Read());

    },

           Read: function() {
                console.log('start to read');
                var self = this.view;
                this.rpc('/web/dataset/search_read', {
                    model: this.view.model,
                    fields: fields || false,
                    domain: this.view.domain,
                    context: this.view.context,
                    offset: 0,
                    limit: false
                }).pipe(function (result) {
                    self.ids = result.ids;
                    self._length = result.length;          
                    console.log(result);            
                    return result.records; // Records is the table of the module
                }); 
                console.log('finished to read');
            },    

    }

Then you can access the data :

console.log(result.records); //display all the records
console.log(result.records[id]); //display all column of record #id
console.log(result.records[id]['column']); //display column 'column' of record #id

Then you can just save it in a variable and use it with JQuery in your QWeb file.