How to get some value from user? I write addon. And i am, like some user, want manualy change some value. As example, string, for renaming!
How to do it? Also how to draw panel for this?
Some thing like this maybe.

import bpy

from bpy.types import(
        Panel,
        Operator,
        PropertyGroup
        )

from bpy.props import(
        StringProperty,
        PointerProperty,
        FloatProperty
        )

class HelloWorldPanel(Panel):
    """Creates a Panel in the Scene properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "scene"

    def draw(self, context):
        layout = self.layout

        # you need to get your stored properties to draw them
        scene = context.scene.your_properties 

        col = layout.column()
        col.prop(scene, "string")
        col = layout.column()
        col.prop(scene, "size")
        col = layout.column()
        col.operator("some.thing")

class Add_some_thing(Operator):

    bl_idname = "some.thing"
    bl_label = "Add object"
    bl_description = "some description"

    def execute(self, context):

        # you need to get your stored properties
        scene = context.scene.your_properties 
        # you get some of your properties to use them
        string = scene.string
        size = scene.size

        # you do some thing to use your property with
        bpy.ops.mesh.primitive_cube_add()
        # you can change some of the added object props as the defined in the ui property 
        context.active_object.name = string 
        context.active_object.scale = [size, size, size]
        return {'FINISHED'}

# your properties here
class addon_Properties(PropertyGroup):

    string = StringProperty(
        name = "the name",
        description="name of the object to add",
        default = ""
        )
    size = FloatProperty(
        name = "size",
        description = "size of the object to add",
        default = 1.0,
        )    

classes = (
    HelloWorldPanel,
    addon_Properties,
    Add_some_thing
    )

def register():

    for cls in classes:
        bpy.utils.register_class(cls)
    # you store your properties in the scene
    bpy.types.Scene.your_properties = PointerProperty(type=addon_Properties)

def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    # you delete your properties
    del bpy.types.Scene.your_properties

if __name__ == "__main__":
    register()